feat: cache installs

[dudymas]

what

• use github's cache/restore and cache/save workflows

why

• Some end users hit API limits on app installs
• Constantly reinstalling is a waste of compute, net, and IO

references:

• actions/cache

[goruha]

The logic using cache should be inside actions that perform installation.

for example inside

cloudpoose/setup-atmos

[hans-d]

@dudymas can you resolve the merge conflict?

[dudymas]

@dudymas can you resolve the merge conflict?

@hans-d updated. @goruha , I forget if this is still something we want in 'terraform-plan', or if this was fixed by the atmos install action.

[goruha]

@dudymas thanks for PR.
I think we should split caches .terraform and cli tools cache.

Check this #83