Fixed Docker CI throwing warnings

[0xc60f]

Description

Removed a redundant line setting the Python environment variables.

Resolves #27

Type of change

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• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
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How Has This Been Tested?

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• Ran the Dockerfile and successfully built it with no errors

Checklist

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• I have added tests that prove my fix is effective or that my feature works
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