ci: Lint GitHub Actions workflows with actionlint (#34729)

Added [rhysd/actionlint](https://github.com/rhysd/actionlint/) a static
checker for GitHub Actions workflow files.
Install locally with `brew install actionlint` the run with
`actionlint`.

Inspired by: https://github.com/zed-industries/zed/pull/34704 which
yielded this observation:

> In github actions: 
> 1. strings are truthy
> 2. `${{ }}` will become a string if it doesn't wrap the whole value.
>
> So `if: false && true` becomes `false`
> and `if: ${{ false && true }}` becomes `false`
> but `if: false && ${{ true }}` becomes `"false && true"` which
evaluates true
> The reason you sometimes need `${{ }}` is because YAML doesn't like
`!`
> so `if: !false` is invalid yaml
> and `if: ${{ !false }}` works just fine.

Changes:
- Add `actionlint` job
- Refactor `job_spec` job to be more readable
- Fix all `actionlint` and `shellcheck` errors in Actions workflows (62
in all)
- Add `self-mini-macos` and `self-32vcpu-windows-2022` labels to
self-hosted runners. Not strictly related, but useful if you need to
take a runner out of the rotation (since `macOS`, `self-hosted`, and
`ARM64` are auto-set and cannot be added/removed).
- Change ci.yml macos_relase to target `self-mini-macos` instead of
`bundle` which was previously deprecated.

This would've caught the error fixed in
https://github.com/zed-industries/zed/pull/34704. Here's what that [job
failure](https://github.com/zed-industries/zed/actions/runs/16376993944/job/46279281842?pr=34729)
would've looked like.

Release Notes:

- N/A

.github/workflows/community_release_actions.yml

@@ -18,7 +18,7 @@ jobs:
               URL="https://zed.dev/releases/stable/latest"
           fi
 
-          echo "URL=$URL" >> $GITHUB_OUTPUT
+          echo "URL=$URL" >> "$GITHUB_OUTPUT"
       - name: Get content
         uses: 2428392/gh-truncate-string-action@b3ff790d21cf42af3ca7579146eedb93c8fb0757 # v1.4.1
         id: get-content
@@ -50,9 +50,9 @@ jobs:
           PREVIEW_TAG="${VERSION}-pre"
 
           if git rev-parse "$PREVIEW_TAG" > /dev/null 2>&1; then
-              echo "was_promoted_from_preview=true" >> $GITHUB_OUTPUT
+              echo "was_promoted_from_preview=true" >> "$GITHUB_OUTPUT"
           else
-              echo "was_promoted_from_preview=false" >> $GITHUB_OUTPUT
+              echo "was_promoted_from_preview=false" >> "$GITHUB_OUTPUT"
           fi
 
       - name: Send release notes email