fix: remove duplicate line in docstring

[exemplary-citizen]

SUMMARY

Removed duplicate line in docstring

TESTING INSTRUCTIONS

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ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

cc: @junlincc @villebro

[codecov]

Codecov Report

Merging #16838 (680992d) into master (1cd0124) will decrease coverage by 0.21%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #16838      +/-   ##
==========================================
- Coverage   76.92%   76.71%   -0.22%     
==========================================
  Files        1030     1030              
  Lines       55022    55022              
  Branches     7465     7465              
==========================================
- Hits        42328    42209     -119     
- Misses      12440    12559     +119     
  Partials      254      254              

Flag	Coverage Δ
hive	?
mysql	81.89% <ø> (ø)
postgres	81.91% <ø> (ø)
presto	?
python	81.99% <ø> (-0.42%)	⬇️
sqlite	81.58% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
superset/utils/pandas_postprocessing.py	84.42% <ø> (ø)
superset/db_engines/hive.py	0.00% <0.00%> (-85.19%)	⬇️
superset/db_engine_specs/hive.py	69.76% <0.00%> (-17.06%)	⬇️
superset/db_engine_specs/presto.py	83.47% <0.00%> (-6.49%)	⬇️
superset/views/database/mixins.py	81.03% <0.00%> (-1.73%)	⬇️
superset/connectors/sqla/models.py	85.59% <0.00%> (-1.66%)	⬇️
superset/models/core.py	89.26% <0.00%> (-0.74%)	⬇️
superset/db_engine_specs/base.py	88.17% <0.00%> (-0.39%)	⬇️
superset/utils/core.py	89.84% <0.00%> (-0.13%)	⬇️

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[exemplary-citizen]

@villebro the failure is unrelated. This PR should be ready to merge.