fix: use mutate repo for queries with locks

[jsw800]

https://discord.com/channels/711271361523351632/1511392095917576482/1511392095917576482

I ran onto this issue via ash_oban:

ash_oban uses Ash.Query.lock(query, :for_update) to read records before running the trigger on the returned records. Since this is an Ash.Query, the logic here assumes that we can use the reader for this operation and calls the repo function with :read as the argument, instead of :mutate. However, in practice we cannot use LOCK FOR UPDATE in a read-only transaction, so postgres just borks when trying to run these against a reader.

This PR updates the logic so queries with locks use :mutate when getting the repo. I'm open to alternative ideas for how to handle this!

Contributor checklist

Leave anything that you believe does not apply unchecked.

• I accept the AI Policy, or AI was not used in the creation of this PR.
• Bug fixes include regression tests
• Chores
• Documentation changes
• Features include unit/acceptance tests
• Refactoring
• Update dependencies

[zachdaniel]

@jsw800 code looks good, just one warning 😄

[jsw800]

@zachdaniel updated!

[zachdaniel]

🚀 Thank you for your contribution! 🚀