Respect configured primary key type in migration

[MSchmidt]

Instead of changing the migration manually this will respect the setting from the rails project. Implementation is the same as ActiveStorage uses.

[excid3]

This is great @MSchmidt! Didn't realize ActiveStorage had this and had wanted a solution for a while like this.

[MSchmidt]

Oh you are absolutely right. I adjusted this in my project and then messed the PR up. Will fix

[MSchmidt]

PR now adjusted for standardrb and remove a note from docs that does not apply anymore.

[excid3]

Perfect. Thanks again for this. Super duper handy and nice to see that Rails uses this approach internally!

[MSchmidt]

Thanks for merging so quickly. Wondering if this should be part of ActiveRecord::Migration then. Not very DRY if every project needs the same few lines of code.

[excid3]

Sure seems like it could be extracted as a couple methods for easy access because any Rails engine with migrations should use it. Maybe you could get it in before Rails 7.1?

Tag me on the PR if you make one to Rails!