[vinsymoyya]

Issue #, if available: Fixes #952

Description of changes

Resolve the requirements manifest to an absolute path and run uv pip install from its directory. Relative wheel and local package references now resolve beside the manifest, including when a function is built from its parent directory. Artifact paths continue to resolve against the caller's working directory.

The change is limited to requirements-based builds; workspace discovery and pyproject builds are outside its scope.

Description of how you validated changes

• Before the fix, the unit regression and all four real wheel-install cases failed with the expected incorrect path.
• After the fix, 63 focused unit, functional, and offline integration checks pass locally.
• Fork CI for commit 9e51371 passed on Linux and Windows with Python 3.13: 1,021 unit/functional tests and 24 UV integration tests per OS, Ruff, Black, and the 94% coverage gate (94.53% Linux; 94.44% Windows).
• Integration regressions use a local wheel and cover absolute/relative build paths with both experimental-flag settings.

Checklist

• Review the generative AI contribution guidelines

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.