Add back matrix tests, up to 1.25

Author: stefanvanburen

.github/workflows/ci.yaml

@@ -13,6 +13,9 @@ permissions:
 jobs:
   ci:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go-version: [1.23.x, 1.24.x, 1.25.x]
     steps:
       - name: Checkout Code
         uses: actions/checkout@v4
@@ -21,8 +24,13 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v5
         with:
-          go-version-file: go.mod
+          go-version: ${{ matrix.go-version }}
       - name: Test
         run: make test
       - name: Lint
+        # Often, lint & gofmt guidelines depend on the Go version. To prevent
+        # conflicting guidance, run only on the most recent supported version.
+        # For the same reason, only check generated code on the most recent
+        # supported version.
+        if: matrix.go-version == '1.25.x'
         run: make checkgenerate && make lint