chore: move scripts to scripts directory and remove unused script

Another tidy-up commit that attempts to get the master branch
into a slightly cleaner shape. I've migrated all the used scripts
into the scripts directory and updated their references in CI.

I've also deleted the goimports.sh script as that's no longer
referenced and it's likely no longer in use.

The final thing for this commit is adding the -race flag to the
test commad in `.mise.toml` to ensure we're race testing when
running our tests.