clean up warnings during Linux install

[drammock]

would be nice if users (on Linux) didn't see this right at the beginning of the installation output:

entry_point.py:256: DeprecationWarning: Python 3.14 will, by default, filter extracted tar archives and reject files or modify their metadata. Use the filter argument to control this behavior.

[matthew-brett]

@jakirkham - is this a Conda constructor issue, do you know?

[drammock]

I think this is (not yet) addressed by conda/conda-build#5390