Publish 3.15.0rc1 to main channel; remove old python3.1 symlink

[h-vetinari]

There was one crucial thing I forgot in #908: publish the builds to the main channel again. In the meantime, pick up some useful bits and pieces:

• 64b26eb from [3.14] Revert 907 #909
• 2ca7532 from [3.14] don't move python.dll into libpython on windows #911
• FixDrop python3.1 symlink #910
• the moral equivalent of the dependency clean-ups in 636474b (which had to be reverted for #908)

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe/meta.yaml) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipe/meta.yaml:

• ℹ️ The recipe is not parsable by parser conda-souschef (grayskull). This parser is not currently used by conda-forge, but may be in the future. We are collecting information to see which recipes are compatible with grayskull.
• ℹ️ The recipe is not parsable by parser conda-recipe-manager. The recipe can only be automatically migrated to the new v1 format if it is parseable by conda-recipe-manager.

_{This message was generated by GitHub Actions workflow run https://github.com/conda-forge/conda-forge-webservices/actions/runs/33363981082. Examine the logs at this URL for more detail.}

[h-vetinari]

Gentle ping @isuruf, this is the last piece for the 3.15 migration. If you don't like bfad55b, I'm happy to rebase that out

[isuruf]

bfad55b

We can keep it for this branch, but let's not backport it.

[h-vetinari]

We can keep it for this branch, but let's not backport it.

I agree, wasn't planning to. IMO it fits nicely since the release of 3.15 goes hand in hand with the EOL of 3.10, which was the release that required this work-around in the first place.