Add `cache-save: false` option

[akx]

Description

This PR adds a new cache-save: false option to opt out of saving the cache. As described in the documentation:

For some scenarios, it may be useful to only save a given subset of dependencies, but restore more of them for other workflows. For instance, there may be a heavy extras dependency that you do not need your entire test matrix to download, but you want to download and test it separately without it being saved in the cache archive for all runs.

To achieve this, you can use cache-save: false on the run that uses the heavy dependency.

Related issue

I only found the related issue after implementing this: #751.

Check list

• [x] Mark if documentation changes are required.
• [x] Mark if tests were added or updated to cover the changes.

[akx]

Rebased on v5.

@dmitry-shibanov Could you review this, please?

[ozancaglayan]

Could someone please take an action for this PR and release a new version? 🙏