ci/gha: run all github CI once a week on main

This is to ensure our CI is not rotting away when there are no new PRs
or merges.

Signed-off-by: Kir Kolyshkin <[email protected]>

Author: kolyshkin

.github/workflows/test.yml

@@ -7,6 +7,9 @@ on:
       - main
       - release-*
   pull_request:
+  schedule:
+    # Runs at 00:00 UTC every Monday
+    - cron: '0 0 * * 1'
 permissions:
   contents: read
 

.github/workflows/validate.yml

@@ -7,6 +7,9 @@ on:
       - main
       - release-*
   pull_request:
+  schedule:
+    # Runs at 00:00 UTC every Monday
+    - cron: '0 0 * * 1'
 env:
   GO_VERSION: 1.24
 permissions: