Replace remaining calls to testing.Short where possible. (#110765)

* Replace remaining calls to testing.Short where possible.
* Update style guide.
* Revert change in TestAlertmanager_ExtraDedupStage, as it doesn't work.
* Make TestAlertRulePostExport into integration test.

pkg/tests/apis/plugins/discovery_test.go

@@ -4,12 +4,12 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+
+	"github.com/grafana/grafana/pkg/util/testutil"
 )
 
-func TestPluginsIntegrationDiscovery(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping integration test")
-	}
+func TestIntegrationPluginsIntegrationDiscovery(t *testing.T) {
+	testutil.SkipIntegrationTestInShortMode(t)
 
 	t.Run("discovery", func(t *testing.T) {
 		helper := setupHelper(t)