Improve testing init, clean up webhook tests (#37412)

Avoid webhook test fixtures affect other tests (be triggered)

Also fixed more testing problems including path init, global config
pollution & conflict

---------

Signed-off-by: silverwind <me@silverwind.io>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: wxiaoguang <2114189+wxiaoguang@users.noreply.github.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>

services/webhook/deliver.go

@@ -36,10 +36,7 @@ import (
 
 func newDefaultRequest(ctx context.Context, w *webhook_model.Webhook, t *webhook_model.HookTask) (req *http.Request, body []byte, err error) {
 	switch w.HTTPMethod {
-	case "":
-		log.Info("HTTP Method for %s webhook %s [ID: %d] is not set, defaulting to POST", w.Type, w.URL, w.ID)
-		fallthrough
-	case http.MethodPost:
+	case "", http.MethodPost:
 		switch w.ContentType {
 		case webhook_model.ContentTypeJSON:
 			req, err = http.NewRequest(http.MethodPost, w.URL, strings.NewReader(t.PayloadContent))