Use generic-unix tar.xz artifact in dockerfile

[MarcialRosales]

Proposed Changes

Fix issue with the command make docker-image. It was failing because it was not locating the generic-unix file.
The Makefile is uncompressing the generic-unix for no reason. It is not necessary as the dockerfile does not use it. Instead, it expects the uncompressed version. This PR should also remove that command which uncompresses the generic-unix file.

These changes are already addressed by this other PR #11042

Types of Changes

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• Bug fix (non-breaking change which fixes issue #NNNN)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause an observable behavior change in existing systems)
• Documentation improvements (corrections, new content, etc)
• Cosmetic change (whitespace, formatting, etc)
• Build system and/or CI