Fix panel drag leaking through overlay (#10035)

Closes #10017. While reworking the `overlay` element in #9911, I did not
realize that all overlay elements called `defer_draw` with a priority of
`1`.

/cc @as-cii 

Not including release notes, since it was only present in nightly.

Release Notes:

- N/A
c126fdb616Bennet Bo Fenner committed on 4/1/2024, 10:31:19 AM· committed by GitHubparent5602593
9 files changedLine totals unavailable