.asf.yaml: Enable rebase and merge option for PRs. This preserves linear history. We should prefer squash merges, but this is a useful option if we are 100% sure each commit will build and there is a high likelihood that a commit will either be reverted or cherry-picked.

Author: NightOwl888

.asf.yaml

@@ -41,7 +41,7 @@ github:
     # can either be: DEFAULT | PR_TITLE | PR_TITLE_AND_COMMIT_DETAILS | PR_TITLE_AND_DESC
     squash_commit_message: PR_TITLE
     merge: false
-    rebase: false
+    rebase: true
 
   rulesets:
     - name: "Main Branch Protection"