ci: Add "ci-ok" job

Adds a dummy ci-ok job that depends on the lint and test job matrix.
This will allow us to add a single Required Status Check to the
protected branch instead of trying to add every variation of the test
job matrix to it.

.github/workflows/ci.yml

@@ -85,9 +85,19 @@ jobs:
       name: Install golangci-lint
       with:
         version: latest
-        args: --version  # make lint will run the linter
+        args: --help  # make lint will run the linter
 
     - name: Lint
       run: make lint GOLANGCI_LINT_ARGS=--out-format=github-actions
       # Write in a GitHub Actions-friendly format
       # to annotate lines in the PR.
+
+  # ci-ok is a dummy job that runs after test and lint.
+  # It provides a job for us to attach a Required Status Check to.
+  ci-ok:
+    name: OK
+    runs-on: ubuntu-latest
+    needs: [test, lint]
+    steps:
+    - name: Success
+      run: echo "All checks passed."