CI: Upgrade actions/checkout to v3

actions/checkout's only change between v2 and v3 is an internal switch
to node 16 which wont effect our usage of it at all.

.github/workflows/libjs-test262.yml

@@ -19,28 +19,28 @@ jobs:
           rm -rf "${{ github.workspace }}/*"
 
       - name: Checkout SerenityOS/serenity
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       - name: Checkout linusg/libjs-test262
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
           repository: linusg/libjs-test262
           path: libjs-test262
 
       - name: Checkout linusg/libjs-website
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
           repository: linusg/libjs-website
           path: libjs-website
 
       - name: Checkout tc39/test262
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
           repository: tc39/test262
           path: test262
 
       - name: Checkout tc39/test262-parser-tests
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
           repository: tc39/test262-parser-tests
           path: test262-parser-tests

.github/workflows/manpages.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-22.04
     if: always() && github.repository == 'SerenityOS/serenity' && github.ref == 'refs/heads/master'
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: r-lib/actions/setup-pandoc@v1
         with:
           pandoc-version: '2.13'

.github/workflows/pvs-studio-static-analysis.yml

@@ -12,7 +12,7 @@ jobs:
       PVS_STUDIO_ANALYSIS_ARCH: i686
     if: always() && github.repository == 'SerenityOS/serenity' && github.ref == 'refs/heads/master'
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: "Configure PVS-Studio Repository"
         run: |

.github/workflows/sonar-cloud-static-analysis.yml

@@ -15,7 +15,7 @@ jobs:
       SONAR_SERVER_URL: "https://sonarcloud.io"
       SONAR_ANALYSIS_ARCH: i686
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
         with:
           fetch-depth: 0  # Shallow clones should be disabled for a better relevancy of analysis
 

.github/workflows/twitter.yml

@@ -8,7 +8,7 @@ jobs:
     if: always() && github.repository == 'SerenityOS/serenity' && github.ref == 'refs/heads/master'
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: actions/setup-node@v2
         with:
           node-version: '14'