CI: create tap audit job

This will reduce the time it takes for the tap-syntax job
to complete (currently that is the slowest one) and will
allow us to audit casks as well as formulae (casks weren't
getting audited before in CI).

.github/workflows/tests.yml

@@ -85,11 +85,6 @@ jobs:
       - name: Run brew style on homebrew-core
         run: brew style --display-cop-names homebrew/core
 
-      - name: Run brew audit --skip-style on homebrew-core for macOS
-        run: brew audit --skip-style --except=version --tap=homebrew/core
-        env:
-          HOMEBREW_SIMULATE_MACOS_ON_LINUX: 1
-
       - name: Set up all Homebrew taps
         run: |
           brew tap homebrew/aliases
@@ -108,12 +103,6 @@ jobs:
           # brew style doesn't like world writable directories
           sudo chmod -R g-w,o-w "$(brew --repo)/Library/Taps"
 
-      - name: Run brew readall on all taps
-        run: brew readall --eval-all --aliases
-
-      - name: Run brew audit --skip-style on all taps
-        run: brew audit --eval-all --skip-style --except=version --display-failures-only
-
       - name: Run brew style on official taps
         run: |
           brew style --display-cop-names homebrew/bundle \
@@ -133,6 +122,49 @@ jobs:
                                          homebrew/cask-fonts \
                                          homebrew/cask-versions
 
+  tap-audit:
+    name: tap audit
+    needs: syntax
+    if: startsWith(github.repository, 'Homebrew/')
+    runs-on: macos-12
+    env:
+      HOMEBREW_NO_INSTALL_FROM_API: 1
+    steps:
+      - name: Set up Homebrew
+        id: set-up-homebrew
+        uses: Homebrew/actions/setup-homebrew@master
+
+      - name: Cache Bundler RubyGems
+        uses: actions/cache@v1
+        with:
+          path: ${{ steps.set-up-homebrew.outputs.gems-path }}
+          key: ${{ runner.os }}-rubygems-${{ steps.set-up-homebrew.outputs.gems-hash }}
+          restore-keys: ${{ runner.os }}-rubygems-
+
+      - name: Install Bundler RubyGems
+        run: brew install-bundler-gems --groups=sorbet
+
+      - name: Set up Homebrew cask and formula taps
+        run: |
+          brew tap homebrew/cask
+          brew tap homebrew/cask-drivers
+          brew tap homebrew/cask-fonts
+          brew tap homebrew/cask-versions
+          brew tap homebrew/core
+
+      - name: Run brew readall on all taps
+        run: brew readall --eval-all --aliases
+
+      - name: Run brew audit --skip-style on formulae
+        run: brew audit --skip-style --except=version --display-failures-only --tap=homebrew/core
+
+      - name: Run brew audit --skip-style on casks
+        run: |
+          brew audit --skip-style --except=version --display-failures-only --tap=homebrew/cask
+          brew audit --skip-style --except=version --display-failures-only --tap=homebrew/cask-drivers
+          brew audit --skip-style --except=version --display-failures-only --tap=homebrew/cask-fonts
+          brew audit --skip-style --except=version --display-failures-only --tap=homebrew/cask-versions
+
   vendored-gems:
     name: vendored gems
     needs: syntax