paused pytorch 2.8 migration awaiting cudnn fix

[das-intensity]

Checklist

• Used a personal fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• Reset the build number to 0 (if the version changed)
• Re-rendered with the latest conda-smithy (Use the phrase @conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• Ensured the license file is being packaged.

As per @h-vetinari's comment #7713 (comment) we should pause this waiting on cudnn

[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.

[h-vetinari]

Thanks for being proactive here.

The migration has run pretty smoothly for packages not depending on cudnn, so it's probably not necessary to pause the migration - we just leave those PRs open where feedstocks fail because of interactions with cudnn.

For context: This is about conda-forge/cudnn-feedstock#124, which is a bug/regression in cudnn packaging.

[das-intensity]

No worries, just trying to learn the ropes as much as possible. Hadn't paused a migration so figured I'd learn how :)