Use GitHub Actions Ubuntu 22.04

It has `brew` in the `PATH`.

Also, while we're here, fix `actions/setup-ruby` deprecation.

.github/workflows/scheduled.yml

@@ -18,7 +18,7 @@ permissions:
 jobs:
   generate:
     if: startsWith( github.repository, 'Homebrew/' )
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Set up Git repository
         uses: actions/checkout@main
@@ -31,7 +31,7 @@ jobs:
         uses: Homebrew/actions/setup-homebrew@master
 
       - name: Set up Ruby
-        uses: actions/setup-ruby@main
+        uses: ruby/setup-ruby@v1
         with:
           ruby-version: "2.7"
 

.github/workflows/tests.yml

@@ -11,7 +11,7 @@ concurrency:
 
 jobs:
   tests:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Set up Git repository
         uses: actions/checkout@main
@@ -21,7 +21,7 @@ jobs:
         uses: Homebrew/actions/setup-homebrew@master
 
       - name: Set up Ruby
-        uses: actions/setup-ruby@main
+        uses: ruby/setup-ruby@v1
         with:
           ruby-version: "2.7"
 

.github/workflows/triage-issues.yml

@@ -29,7 +29,7 @@ jobs:
           contains(github.event.pull_request.labels.*.name, 'stale')
         )
       )
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Mark/Close Stale Issues and Pull Requests
         uses: actions/stale@v6
@@ -54,7 +54,7 @@ jobs:
           contains(github.event.pull_request.labels.*.name, 'stale')
         )
       )
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Mark/Close Stale `bump-formula-pr` and `bump-cask-pr` Pull Requests
         uses: actions/stale@v6
@@ -71,7 +71,7 @@ jobs:
 
   lock-threads:
     if: startsWith(github.repository, 'Homebrew/') && github.event_name != 'issue_comment'
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Lock Outdated Threads
         uses: dessant/lock-threads@e460dfeb36e731f3aeb214be6b0c9a9d9a67eda6