chore: QoL improvements to tests (#7917)

- Use mock helper functions, instead of home-brew solutions.
- Disable cron jobs that are not important to be run during integration tests and might even interfere.
- Avoid sleeping unnecessary, if there's some requirement then sleep or retry until that requirement is met.
- Avoid trying to deliver webhooks that will always result in a failure.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/7917
Reviewed-by: Michael Kriese <michael.kriese@gmx.de>
Co-authored-by: Gusted <postmaster@gusted.xyz>
Co-committed-by: Gusted <postmaster@gusted.xyz>

modules/queue/manager_test.go

@@ -8,17 +8,14 @@ import (
 	"testing"
 
 	"forgejo.org/modules/setting"
+	"forgejo.org/modules/test"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
 func TestManager(t *testing.T) {
-	oldAppDataPath := setting.AppDataPath
-	setting.AppDataPath = t.TempDir()
-	defer func() {
-		setting.AppDataPath = oldAppDataPath
-	}()
+	defer test.MockVariableValue(&setting.AppDataPath, t.TempDir())()
 
 	newQueueFromConfig := func(name, cfg string) (*WorkerPoolQueue[int], error) {
 		cfgProvider, err := setting.NewConfigProviderFromData(cfg)