[KeyVault] Remove references to six package

[ponopono0322]

Description

Fix #22373.
Removed six package

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• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.

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• Title of the pull request is clear and informative.
• There are a small number of commits, each of which have an informative message. This means that previously merged commits do not appear in the history of the PR. For more information on cleaning up the commits in your PR, see this page.

Testing Guidelines

• Pull request includes test coverage for the included changes.

[ghost]

Thank you for your contribution ponopono0322! We will review the pull request and get back to you soon.

[ponopono0322]

Summary of changes

1. six.moves.urllib_parse
   Following docs, same as using urllib.

link = "https://azure.microsoft.com/en-us/"

# Before
import six
q = six.moves.urllib_parse.urlparse(link)
print(p)
# >>> ParseResult(scheme='https', netloc='azure.microsoft.com', path='/en-us/', params='', query='', fragment='')

# After
from urllib import parse
p = parse.urlparse(link)
print(q)
# >>> ParseResult(scheme='https', netloc='azure.microsoft.com', path='/en-us/', params='', query='', fragment='')

2. six.raise_from
   Following docs, six.raise_from(exc_value, exc_value_from) same as raise exc_value from exc_value_from

# Before
from six import raise_from
try:
    zero_div = 1 / 0
except Exception as ex:
    raise_from(ValueError("zero div"), ex, )
# >>> ValueError: zero div

# After
try:
    zero_div = 1 / 0
except Exception as ex:
    raise ValueError("zero div") from ex
# >>> ValueError: zero div

3. six.with_metaclass
   In python3, metaclass declaration has changed. I referred to stackoverflow and docs.

from enum import Enum, EnumMeta
class _CaseInsensitiveEnumMeta(EnumMeta):
    def __getitem__(self, name):
        return super().__getitem__(name.upper())

    def __getattr__(cls, name):
        try:
            return cls._member_map_[name.upper()]
        except KeyError:
            raise AttributeError(name)

# Before
from six import with_metaclass
class DeletionRecoveryLevel(with_metaclass(_CaseInsensitiveEnumMeta, str, Enum)):
    PURGEABLE = "Purgeable"
    RECOVERABLE_PURGEABLE = "Recoverable+Purgeable"
    RECOVERABLE = "Recoverable"
    RECOVERABLE_PROTECTED_SUBSCRIPTION = "Recoverable+ProtectedSubscription"
    CUSTOMIZED_RECOVERABLE_PURGEABLE = "CustomizedRecoverable+Purgeable"
    CUSTOMIZED_RECOVERABLE = "CustomizedRecoverable"
    CUSTOMIZED_RECOVERABLE_PROTECTED_SUBSCRIPTION = "CustomizedRecoverable+ProtectedSubscription"


print(type(DeletionRecoveryLevel), DeletionRecoveryLevel)
print(type(DeletionRecoveryLevel.PURGEABLE), DeletionRecoveryLevel.PURGEABLE)
# >>> <class '__main__._CaseInsensitiveEnumMeta'> <enum 'DeletionRecoveryLevel'>
# >>> <enum 'DeletionRecoveryLevel'> DeletionRecoveryLevel.PURGEABLE

# After
class DeletionRecoveryLevel(str, Enum, metaclass=_CaseInsensitiveEnumMeta):
    PURGEABLE = "Purgeable"
    RECOVERABLE_PURGEABLE = "Recoverable+Purgeable"
    RECOVERABLE = "Recoverable"
    RECOVERABLE_PROTECTED_SUBSCRIPTION = "Recoverable+ProtectedSubscription"
    CUSTOMIZED_RECOVERABLE_PURGEABLE = "CustomizedRecoverable+Purgeable"
    CUSTOMIZED_RECOVERABLE = "CustomizedRecoverable"
    CUSTOMIZED_RECOVERABLE_PROTECTED_SUBSCRIPTION = "CustomizedRecoverable+ProtectedSubscription"


print(type(DeletionRecoveryLevel), DeletionRecoveryLevel)
print(type(DeletionRecoveryLevel.PURGEABLE), DeletionRecoveryLevel.PURGEABLE)
# >>> <class '__main__._CaseInsensitiveEnumMeta'> <enum 'DeletionRecoveryLevel'>
# >>> <enum 'DeletionRecoveryLevel'> DeletionRecoveryLevel.PURGEABLE

5. six.ensure_str
   Following docs, six.ensure_str(s, encoding='utf-8', errors='strict') same as str(s).
   It is necessary to confirm whether str guarantees utf-8 or whether it is okay to ignore it.

r1 = """{"body": "something", "header": "anything"}"""
# Before
import six
print(type(six.ensure_str(r1)))
# >>> <class 'str'>

# After
print(type(str(r1)))
# >>> <class 'str'>

6. six.string_types
   Following docs, string_types same as str

# Before
import six
print("True") if isinstance("key", six.string_types) else print("False")
# >>> True

# After
print("True") if isinstance("key", str) else print("False")
# >>> True

7. six.byte2int
   Following docs, six.byte2int(bs) same as bs[0].

bs = bytes(5)

# Before
import six
print(bs, type(six.byte2int(bs)), six.byte2int(bs))
# >>> b'\x00\x00\x00\x00\x00' <class 'int'> 0

# After
print(bs, type(bs[0]), bs[0])
# >>> b'\x00\x00\x00\x00\x00' <class 'int'> 0

I checked it reference, type and some tests, but it still needs to be modified. I ran a test proxy for clear results, but I couldn't confirm that it was working properly due to POST error at the moment (even in the main branch).
ERROR says:

args = (<test_examples_crypto.TestCryptoExamples object at 0x10353c490>, <azure.keyvault.keys._client.KeyClient object at 0x103b40bb0>)
kwargs = {'is_hsm': False, 'managed_hsm_url': 'https://managedhsmvaultname.vault.azure.net', 'vault_url': 'https://vaultname.vault.azure.net'}
trimmed_kwargs = {'is_hsm': False, 'managed_hsm_url': 'https://managedhsmvaultname.vault.azure.net', 'vault_url': 'https://vaultname.vault.azure.net'}
test_id = 'sdk/keyvault/azure-keyvault-keys/tests/recordings/test_examples_crypto.pyTestCryptoExamplestest_encrypt_decrypt[7.3_vault]', variables = {}
combined_call = <function recorded_by_proxy.<locals>.record_wrap.<locals>.combined_call at 0x10399a700>, test_variables = None
error_body = {'Message': 'Unable to find a record for the request POST https://vaultname.vault.azure.net/keys/livekvtestcrypto-test...coding> values differ, request <gzip, deflate, br>, record <gzip, deflate>\nBody differences:\n', 'Status': 'NotFound'}
message = 'Unable to find a record for the request POST https://vaultname.vault.azure.net/keys/livekvtestcrypto-test-encrypt-key...rences:\n    <Accept-Encoding> values differ, request <gzip, deflate, br>, record <gzip, deflate>\nBody differences:\n'
error_with_message = ResourceNotFoundError('Unable to find a record for the request POST https://vaultname.vault.azure.net/keys/livekvtestc...ences:\n    <Accept-Encoding> values differ, request <gzip, deflate, br>, record <gzip, deflate>\nBody differences:\n')

[mccoyp]

Thank you so much for opening a PR! I'll follow up on the generated code's use of six.with_metaclass and will let you know if I can fix that in a separate PR.

[mccoyp]

Closing in favor of #26150