Adds undeclared dependency on setuptools

[groodt]

Before submitting

• Was this discussed/agreed via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did all existing and newly added tests pass locally?

What does this PR do?

Fixes the undeclared dependency on setuptools. There is an undeclared dependency on setuptools here

utilities/src/lightning_utilities/core/imports.py

Line 14 in 84cafbc

import pkg_resources

While it is true that most python environments will have setuptools pre-installed, this is not always safe to assume.

Fixes # (issue).

PR review

Anyone in the community is free to review the PR once the tests have passed.
If we didn't discuss your PR in GitHub issues there's a high chance it will not be merged.

[awaelchli]

We don't have this dep in lightning either, should it be there? @Borda and @carmocca know better about this than me :)

[Borda]

We don't have this dep in lightning either, should it be there? @Borda and @carmocca know better about this than me :)

@groodt Where is it used? I guess in setup.py ony, right?