fix: respect priority case

[lyz-code]

Summary

Let the user specify priorities in lowercase [#a] instead of [#A], which needs less keys when setting the priority directly in capture templates.

The current codebase supports this and it works well when using org_priority_up and org_priority_down. However the org_priority did nothing.

This small change makes it work.

Changes

• List changes here

Checklist

I confirm that I have:

• Followed the
  Conventional Commits
  specification (e.g., feat: add new feature, fix: correct bug,
  docs: update documentation).
• My PR title also follows the conventional commits specification.
• Updated relevant documentation, if necessary.
• Thoroughly tested my changes.
• Added tests (if applicable) and verified existing tests pass with
  make test.
• Checked for breaking changes and documented them, if any.