ci: Change Renovate schedule to run every 2 hours (#74)

Author: warnyul

.github/workflows/renovate.yml

@@ -45,7 +45,7 @@ on:
   schedule:
     # The "*" (#42, asterisk) character has special semantics in YAML, so this
     # string has to be quoted.
-    - cron: '*/15 * * * *'
+    - cron: '0 */2 * * *'
 jobs:
   renovate:
     runs-on: ubuntu-24.04