CI: Run lint on 1.17 for now

staticcheck is expected to have support for generics-based code in a few
weeks. Meanwhile, we can run lint only on 1.17.

.github/workflows/go.yml

@@ -15,8 +15,11 @@ jobs:
       matrix:
         go: ["1.17.x", "1.18.x"]
         include:
-        - go: 1.18.x
-          latest: true
+        - go: 1.17.x
+          lint: true
+          # TODO: Switch to 1.18 after
+          # https://github.com/dominikh/go-tools/issues/1166
+          # is resolved.
 
     steps:
     - name: Setup Go
@@ -43,7 +46,7 @@ jobs:
         (cd zapgrpc/internal/test && go mod download)
 
     - name: Lint
-      if: matrix.latest
+      if: matrix.lint
       run: make lint
 
     - name: Test