Modernize GitHub Actions workflow for current Go toolchain.

.github/workflows/go.yml

@@ -4,29 +4,48 @@ on:
   push:
   pull_request:
 
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
 
   build:
     name: Build
     runs-on: ubuntu-latest
     steps:
 
-    - name: Set up Go 1.x
-      uses: actions/setup-go@v2
-      with:
-        go-version: ^1.13
-      id: go
-
     - name: Check out code into the Go module directory
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
 
-    - name: Get dependencies
-      run: |
-        go get -d -v ./events
-        go get golang.org/x/lint/golint
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version: stable
+        # The module has no external dependencies, so there is nothing to cache.
+        cache: false
 
     - name: Build
-      run: go build -v ./events
+      run: go build -v ./...
+
+    - name: Vet
+      run: go vet ./...
 
-    - name: Test
-      run: golint ./events
+    - name: Check formatting
+      continue-on-error: true
+      run: |
+        unformatted=$(gofmt -l .)
+        if [ -n "$unformatted" ]; then
+          echo "The following files are not gofmt-formatted:"
+          echo "$unformatted"
+          exit 1
+        fi
+
+    - name: Static analysis
+      continue-on-error: true
+      run: |
+        go install honnef.co/go/tools/cmd/staticcheck@v0.7.0
+        staticcheck ./...