Mw/circle ci stable release testing

[wilkermichael]

Changes proposed in this PR:

• This PR serves to implement the new testing strategy required by our support of stable releases
• As always, you can go through my PR commit by commit for more context
• After this PR we should support the following testing strategy
  • Nightly cloud/kind on main
  • Nightly cloud/kind on release branches (once backported)
  • PR kind tests off of every branch
  • Nightly Consul compatibility tests off of main

What's New:

• New separate cleanup nightly, this is so that the cleanup step does not conflict with multiple running cloud steps
• New scheduled nightly that will run on release branches
• Separate scheduled nightly that will run on main branch, this is so the release branch and main branch nightlies can run at a separate cadence (maybe we'll want to run release nightlies one night a week? a "weekly"?). For now both main and release will run nightly
• Nightlies now also run the kind-tproxy acceptance tests
• For now, all nightlies will run at 5 pm PST (12 am UTC) and cleanup will run at 5 am PST (12 pm UTC). We can re-evaluate later what the testing cadence should be.

How I've tested this PR:

• Ran nightlies at an accelerate schedule. Some tests in the clouds fail, but talked with Iryna these will be fixed in a later PR
• 👀
  How I expect reviewers to test this PR:
  👀

Checklist:

• Tests added
• [N/A] CHANGELOG entry added

  HashiCorp engineers only, community PRs should not add a changelog entry.
  Entries should use present tense (e.g. Add support for...)

[ndhanushkodi]

Amazing work on this Michael!