Disable the golangci-lint-action's own Go mod & Go build caches

[ulucinar]

Description of your changes

We already manage Go mod & build caches for the CI jobs of the official provider repositories to speed up the build times. The golangci-lint action that we use to run the linter can itself maintain the Go build and mod caches, however, with a different cache key than we use, with the syntax explained here.

This PR proposes to disable that action's own Go build and mod caches and use the caches we explicitly maintain, the caches with the keys Linux-{build, pkg}-lint-. This should also prevent the occasional tar errors we observe for these cache files.

An alternative would just be not populating the build and mod caches explicitly from the Linux-{build, pkg}-lint- keys and letting the action manage its own cache. I did not choose this way because it's less efficient than building a single cache with (almost) the same contents (please see the note below).

Note: The action caches the whole pkg folder instead of the pkg/mod folder as the caches we explicitly maintain do. The action's cache also has an expiration date, i.e., even if the contents of the go.mod file does not change, the cache will expire after a certain period of time (one week). From a practical point of view, the explicitly maintained cache should also be fine though.

I have:

• Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

Manually tested in the main branch of a fork repo of upbound/provider-aws and upbound/provider-azuread.

[sergenyalcin]

Thanks @ulucinar LGTM!

[ulucinar]

Let's observe how the unified cache approach works. If we spot any issues then we can remove the explicitly maintained cache for the linter.