Upgrade macos runner NodeJS version (#47189) (#47214)

(cherry picked from commit 93e2ae9)

Co-authored-by: Emilio Alvarez Piñeiro <95703246+emilioalvap@users.noreply.github.com>

Author: mergify[bot]

.github/workflows/xpack-heartbeat-macos-unit-tests.yml

@@ -2,7 +2,7 @@ name: xpack-heartbeat-macos-unit-tests
 
 env:
   BEAT: "x-pack/heartbeat"
-  NODEJS_VERSION: "18.20.3"
+  NODEJS_VERSION: "22.20.0"
 
 on:
   workflow_dispatch: