Default to Deno v2?

[sgoudham]

Figured it might be a nice idea to update the setup-deno action to v2 and push out a v2 tag for this repository so that people don't have to specify 2.x as a parameter. That being said, feel free to close this issue as not planned if you're not interested in that.

Also I was looking through the migration guide, it looks as though the deno cache command was merged into deno install command.

Would you happen to know if that impacts this repository in any meaningful way?