ci: Fix check-changed (#3420)

check-changed was breaking when develop -> master PRs were open.
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

ops/docker/ci-builder/check-changed.sh

@@ -27,6 +27,12 @@ else
 	echoerr "$PR"
 	REF=$(echo "$PR" | jq -r ".base.ref")
 
+	if [ "$REF" = "master" ]; then
+		echoerr "Base ref is master, requiring a total rebuild."
+		echo "TRUE"
+		exit 0
+	fi
+
 	echoerr "Base Ref:     $REF"
 	echoerr "Base Ref SHA: $(git show-branch --sha1-name "$REF")"
  	echoerr "Curr Ref:     $(git rev-parse --short HEAD)"