Update minimum go version

[pd93]

Go 1.23 has been released, so it's time to bump our minimum version again.

Previously, we supported 1.21 and 1.22. This PR bumps the minimum version to 1.22 and drops support for 1.21. Our tests/linter will now run against 1.22 and 1.23.

Bumping the minimum version allows us to use some of the features introduced in 1.22. There are a number of changes are relevant to this project, including:

• Ranging over integers directly
  • No more for i := 0; i < len(s); i++ loops. We can now do for i := range len(s).
• Changes to how loop variables are set
  • No need to do weird things like idx := i in closures anymore. It just works.
  • I've updated a test to ensure we're getting the correct behavior.
• The addition of cmp.Or.
• The addition of slices.Concat.

[andreynering]

Awesome, thanks!

[vmaerten]

I saw it on Twitter. I will need to update projects at work too!
Nice work thanks 🔥