Fix neptune-client package available detection

[awaelchli]

What does this PR do?

Fixes #14695

This targets the release/pytorch branch!

Discussed with @carmocca that my immediate fix can directly go to the release branch for the next patch. Note that we don't have the lightning-utilities dependency for this branch.
Meanwhile, @carmocca will push the proper fix to master in #14715 and follow up.

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Did you have fun?

I made sure I had fun coding 🙃

cc @Borda @tchaton @rohitgr7 @Blaizzy @akihironitta

[awaelchli]

@Borda @carmocca

Quick notice:

• changed branch target to release/pytorch
• had to include Combine the pip install commands in conda workflow #14744 for the CI

Is it ok if we rebase-merge it like this? Or do you have a different preference?

[carmocca]

It is okay