ci: upgrade outdated actions and cache deps in PR Checks (master) (#5150)

- Upgrade actions/checkout v3 → v4 in both check_docs and test_go
- Upgrade actions/setup-go v3 → v5 with cache-dependency-path: v2/go.sum
  (enables Go module and build cache, was missing previously)
- Replace bare apt-get update/install with awalsh128/cache-apt-pkgs-action
  for ubuntu-22.04 and ubuntu-24.04 (saves ~30s per Linux job on cache hit,
  consistent with how v3 workflows handle Linux deps)

The test_go condition and trigger types were already correct on master.
Companion to #5149 which makes equivalent changes on the v3-alpha branch.

Co-authored-by: Wails Documentation Agent <agent@wails.local>

Author: leaanthony

.github/workflows/pr-master.yml

@@ -23,7 +23,7 @@ jobs:
     if: ${{ github.repository == 'wailsapp/wails' && github.base_ref == 'master' }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Verify Changed files
         uses: step-security/changed-files@3dbe17c78367e7d60f00d78ae6781a35be47b4a1 # v45.0.1
@@ -59,20 +59,27 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Install linux dependencies (22.04)
+        uses: awalsh128/cache-apt-pkgs-action@latest
         if: matrix.os == 'ubuntu-22.04'
-        run: sudo apt-get update -y && sudo apt-get install -y libgtk-3-dev libwebkit2gtk-4.0-dev build-essential pkg-config
+        with:
+          packages: libgtk-3-dev libwebkit2gtk-4.0-dev build-essential pkg-config
+          version: 1.0
 
       - name: Install linux dependencies (24.04)
+        uses: awalsh128/cache-apt-pkgs-action@latest
         if: matrix.os == 'ubuntu-24.04'
-        run: sudo apt-get update -y && sudo apt-get install -y libgtk-3-dev libwebkit2gtk-4.1-dev build-essential pkg-config
+        with:
+          packages: libgtk-3-dev libwebkit2gtk-4.1-dev build-essential pkg-config
+          version: 1.0
 
       - name: Setup Go
-        uses: actions/setup-go@v3
+        uses: actions/setup-go@v5
         with:
           go-version: ${{ matrix.go-version }}
+          cache-dependency-path: v2/go.sum
 
       - name: Run tests (mac)
         if: matrix.os == 'macos-latest'