Move towards Github Actions + Deprecating old code/tooling

[iuga]

• Adding 2 initial GitHub actions:
  • Build, lint and test golang code
  • Releases on new tags
• Deprecating BuildKite builds
• Deprecating Earthly builds
• Deprecating the revive custom rules.
• Deprecating and removing the generics module.
• Deprecating and removing the bench tooling.

// Deprecated: The "github.com/TriggerMail/lazylru/generic" package has been
// deprecated. Please point all references to "github.com/TriggerMail/lazylru",
// which now includes the generic API.