fix(tests): Also run the tests in isolation in the default profile (#3664)

## Description

This means these tests also work when nextest run locally.

## Breaking Changes

<!-- Optional, if there are any breaking changes document them,
including how to migrate older code. -->

## Notes & open questions

I'm not sure why this wasn't done when the ci profile override was
chosen.  What am I missing?

## Change checklist
<!-- Remove any that are not relevant. -->
- [x] Self-review.

Author: flub

.config/nextest.toml

@@ -9,5 +9,10 @@ filter = 'test(::run_in_isolation::)'
 test-group = 'run-in-isolation'
 threads-required = 32
 
+[[profile.default.overrides]]
+filter = 'test(::run_in_isolation::)'
+test-group = 'run-in-isolation'
+threads-required = 32
+
 [profile.default]
 slow-timeout = { period = "20s", terminate-after = 3 }