lxd/request: Fix request not counted warning

This makes it so that we don't expect the metrics callback to be
present on devlxd endpoints and neither on the `/` endpoint.
Also this avoids using `GetAuthenticationMethodFromCtx` to avoid
creating a import loop

Signed-off-by: hamistao <pedro.ribeiro@canonical.com>

lxd/request/request.go

@@ -78,7 +78,10 @@ func CountStartedRequest(r *http.Request) {
 // The callback function is used to mark the request as completed for the API metrics.
 func MetricsCallback(request *http.Request, result metrics.RequestResult) {
 	callback, err := GetCtxValue[func(metrics.RequestResult)](request.Context(), MetricsCallbackFunc)
-	if err != nil && (strings.HasPrefix(request.URL.Path, "/1.0") || request.URL.Path == "/") {
+
+	// Verify the auth method in the request context to determine if the request comes from the /dev/lxd socket.
+	authMethod, _ := GetCtxValue[string](request.Context(), CtxProtocol)
+	if err != nil && strings.HasPrefix(request.URL.Path, "/1.0") && authMethod != api.AuthenticationMethodDevLxd {
 		// Log a warning if endpoint is part of the main API, and therefore should be counted fot the API metrics.
 		logger.Warn("Request will not be counted for the API metrics", logger.Ctx{"url": request.URL.Path, "method": request.Method, "remote": request.RemoteAddr})
 	} else if err == nil && callback != nil {