Revert "automation: rebase `main` instead of merge"

This reverts commit d083de30789b8c71f58725b274d4db20d0e3f9f6.

.github/workflows/sync-main-to-earlgrey-hwe.yml

diff --git a/.github/workflows/sync-main-to-earlgrey-hwe.yml b/.github/workflows/sync-main-to-earlgrey-hwe.yml
index 8bb7a70..1cb0a1a 100644
--- a/.github/workflows/sync-main-to-earlgrey-hwe.yml
+++ b/.github/workflows/sync-main-to-earlgrey-hwe.yml
@@ -24,8 +24,8 @@
           # Fetch the latest main branch
           git fetch origin main:main
 
-          # Rebase main onto the currently checked-out dev branch
-          git rebase main
+          # Merge main into the currently checked-out dev branch
+          git merge main --no-edit
 
       - name: Generate GitHub App Token
         id: generate-token