v2.0: Apply cosmetic changes to unified scheduler (backport of #1861)

[mergify]

Problem

Summary of Changes

Fixes #

---

This is an automatic backport of pull request #1861 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of b8abc7e has failed:

On branch mergify/bp/v2.0/pr-1861
Your branch is up to date with 'origin/v2.0'.

You are currently cherry-picking commit b8abc7e3a5.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   runtime/src/installed_scheduler_pool.rs

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   unified-scheduler-pool/src/lib.rs

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[ryoqun]

Cherry-pick of b8abc7e has failed:

oh, this is understandable, considering #1854 isn't merged yet...