fix(optimize): 🐛 fixed file resolution on windows

[philippdrebes]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/ngneat/transloco/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Other... Please describe:

What is the current behavior?

Issue Number: #685

What is the new behavior?

Fixes the issue on Windows. However, has yet to be tested on Unix systems.
Has been successfully tested on macOS as well.

Does this PR introduce a breaking change?

• Yes
• No

Other information

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