Tear down the custom release process to revert to manual tags

[Racer159]

Describe what should be investigated or refactored

We would like to go back to manual tagging to provide more flexibility for fixing erroneous tags / pathing in go mods going forward.

We also want to provide some simple docs on how this process works and specifically calling out that we will not be following semantic versioning and will be sticking at v0.x/1.x going forward.

Links to any relevant code

https://github.com/defenseunicorns/pkg/tree/main/internal/release

Additional context

There should still be some simple release automation for generating release notes, just that tagging/managing go mod pathing would be manual going forward.