[CI]: github cache is too aggressive on limiting requests (429)

### Description

Github cache will return 429 (Too Many Requests) way too frequently.
We are not the only ones having this problem. A cursory search will show other projects struggling with it.

I just hit this while working on #3636

I do appreciate that I have been pushing quite a few times (as I need a windows env), but honestly, a single contributor being able to trip it up in a few hours is not a good sign.

We have been discussing this over at #3580 and implemented with #3583 for dependencies building.

I am now using it in #3636 as a convenience speed-up to avoid rebuilding busybox every time - but of course, once this is ready, we can remove it as this task will run rarely.

Still, the problem stand - GHA cache feels *really tight* (not even mentioning the 10G limit).

Any suggestions on what to do?

A. can we somehow convince github to upgrade our tier so we get more horsepower?
B. should we renounce using GH cache (besides the dependency building that is in place and that does give us strong benefits)?
C. should we forbid @apostasie from pushing stuff all the time?
D. can I get a windows laptop? :-)
E. should we consider an alternative cache storage mechanism? like, stuff things into a scratch image and push/pull it to ghcr.io?
F. other ideas?

### Steps to reproduce the issue

_No response_

### Describe the results you received and expected

na

### What version of nerdctl are you using?

na

### Are you using a variant of nerdctl? (e.g., Rancher Desktop)

None

### Host information

_No response_