chore: github settings to only enable squash commits (#747)

Author: Fgerthoffert

.asf.yaml

@@ -0,0 +1,7 @@
+# Documentation/specs available here: https://github.com/apache/infrastructure-asfyaml
+github:
+  enabled_merge_buttons:
+    squash: true
+    squash_commit_message: PR_TITLE
+    merge: false
+    rebase: false