Minor updates to uv project export machinery in PyRosettaCluster

[klimaj]

This minor PR addresses:

• Instead of relying on an exported requirements.txt file from the uv project, the uv.lock file is cached (similar to Pixi which caches the pixi.lock file). The reason for this change is several-fold:
  • The requirements.txt file does not pin the Python version being used to execute the PyRosettaCluster simulation. We were relying on the pyproject.toml file to provide this information, however, if the user doesn't pin the Python version in it, then there's no record of which Python version is being used (other than inspecting the PyRosetta build string or another hack).
  • The uv export command doesn't provide sha256 hashes for custom registries. Now that pyrosetta is shipped quarterly, this disallows using the uv pip sync --require-hashes flag which would match hashes for each requirement, making reproduction more robust. While uv pip compile does support the --generate-hashes flag, again the Python version is not captured in a requirements.txt file.
  • Currently, uv export doesn't support emitting the --find-links paths into the exported requirements.txt file. While uv pip compile does support the --emit-find-links flag, again the Python version is not captured in a requirements.txt file.
• Ensures the self.toml_format attribute is still set for the edge case where the uv pyproject.toml file cannot be automatically located via either the UV_PROJECT environment variable or the current working directory (which currently leads to an AttributeError upon saving results). A more helpful warning message is provided herein.
• Disables two FutureWarnings regarding the filter_results and norm_task_options class attributes being enabled by default, which were introduced in version 2.1.0 (merged ~8/25) and 3.0.0 (merged ~10/25), respectively.

[lyskov]

LGTM!