Build with uv instead of just pip

[jennifgcrl]

Description

Fixes #1323

Type of change

• Documentation change (change only to the documentation, either a fix or a new content)
• Bug fix (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)
• Infra/Build change
• Code refractor

Changes

Please list the changes introduced in this PR:

• build_tools picks uv or python -m pip depending on if pip exists or not
• additional install_and_imports for uv's clean build environments

Checklist:

• I have read and followed the contributing guidelines
• The functionality is complete
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[timmoon10]

uv looks neat, but I'm uncomfortable hard-coding like this until it has wider adoption.

I've written up my thoughts on the root problems at #1323 (comment). I think the best approach for now is to adopt your changes to uninstall_te_wheel_packages and to build TE with build isolation disabled. uv should support this (astral-sh/uv#1715).

As an aside, I agree with @Taytay's assessment that build isolation is not a good fit for the ML ecosystem since it depends on custom, vendor-provided packages that are tricky to install. It's annoying the lengths that the Python developers went to to coerce package maintainers to use build isolation.

[timmoon10]

This is a reasonable change that I would accept on its own. It doesn't fully solve the root issue (the package structure is different when installing from PyPI or from source), so I could imagine users running into problems if they install TE multiple times. But it seems fair to expect users to handle this on their own if they are using a non-standard build environment.

[ksivaman]

This installation should be guarded depending on which framework the extensions are being built for

[jennifgcrl]

@timmoon10 Thanks for looking into this! I've updated the PR to be just the uninstall_te_wheel_packages change.

I think it's easier for me to just maintain a fork than --no-build-isolation since (as far as I can tell) there's no way to tell rye to pass --no-build-isolation to uv.

Do you think we can (for the time being) support both build isolation and no build isolation? One way this might work is: if NVTE_FRAMEWORK contains frameworks that aren't in the current python environment, try installing them; otherwise use the existing package.