[management] Add idp timeout env variable (#4647)

Introduced the NETBIRD_IDP_TIMEOUT environment variable to the management service. This allows configuring a timeout for supported IDPs. If the variable is unset or contains an invalid value, a default timeout of 10 seconds is used as a fallback.

This is needed for larger IDP environments where 10s is just not enough time.

management/server/idp/zitadel.go

@@ -164,9 +164,10 @@ func NewZitadelManager(config ZitadelClientConfig, appMetrics telemetry.AppMetri
 	httpTransport.MaxIdleConns = 5
 
 	httpClient := &http.Client{
-		Timeout:   10 * time.Second,
+		Timeout:   idpTimeout(),
 		Transport: httpTransport,
 	}
+	
 	helper := JsonParser{}
 
 	hasPAT := config.PAT != ""