[ci] Don't fail on cache miss (#32690)

Partially reverts #32686.

PR caches inherit from caches generated in `main`. If it cannot find
that cache, it will create one scoped to just that PR (and PRs that
inherit from it).

There is an edge case where cache eviction can happen in the middle of a
test run. If cache eviction removes a `main` cache, child jobs that
depend on it will start failing because of the `fail-on-cache-miss`
setting.

This PR reverts the default behavior. If this happens, the workflow will
still continue in slow mode where it will `yarn install` child jobs
instead of reusing from cache. This is slower but will at least allow
workflows to continue.

Additionally I added restore keys so that we can fallback to other
caches if present so `yarn install` doesn't need to start over from
scratch.