ci: update actions, set default permissions, and pin by sha

.github/workflows/ci.yml

@@ -6,38 +6,49 @@ on:
   pull_request:
     branches: [ main ]
 
+permissions:
+  contents: read
+
+env:
+  GOTOOLCHAIN: local
+
 jobs:
 
   build:
     strategy:
       fail-fast: false
       matrix:
-        go: ['1.21.x', '1.22.x', '1.23.x']
+        go-version:
+          - "" # leave empty to use go-version-file (use go.mod); see https://github.com/actions/setup-go/issues/450#issuecomment-3620402646
+          - oldstable
+          - stable
 
-    name: Typeurl CI
+    name: ${{ matrix.go-version || 'minimum' }}
     runs-on: ubuntu-24.04
     timeout-minutes: 5
     steps:
 
-    - name: Set up Go ${{ matrix.go }}
-      uses: actions/setup-go@v5
+    - name: Check out code
+      uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      with:
+        path: src/github.com/containerd/typeurl
+        fetch-depth: 25
+        persist-credentials: false
+
+    - name: Set up Go
+      uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6.4.0
       with:
-        go-version: ${{ matrix.go }}
+        go-version: ${{ matrix.go-version }}
+        go-version-file: src/github.com/containerd/typeurl/go.mod # used when go-version is empty.
 
     - name: Setup Go binary path
       shell: bash
       run: |
         echo "GOPATH=${{ github.workspace }}" >> $GITHUB_ENV
         echo "${{ github.workspace }}/bin" >> $GITHUB_PATH
 
-    - name: Check out code
-      uses: actions/checkout@v4
-      with:
-        path: src/github.com/containerd/typeurl
-        fetch-depth: 25
-
     - name: Project Checks
-      uses: containerd/project-checks@v1.1.0
+      uses: containerd/project-checks@d7751f3c375b8fe4a84c02a068184ee4c1f59bc4 # v1.2.2
       with:
         working-directory: src/github.com/containerd/typeurl