ci: only run 'flake check' when we have a new commit

bin/ci

@@ -49,15 +49,23 @@ if [ "${1}" = "update" ]; then
 			continue
 		fi
 
+		current_hash="$(git rev-parse HEAD)"
+
 		if ! nix flake lock --commit-lock-file --update-input "$inp"; then
 			handle_update_fail "$inp"
 			continue
 		fi
 
+		maybe_new_hash="$(git rev-parse HEAD)"
+
+		if [ "${current_hash}" != "${maybe_new_hash}" ]; then
 			if ! nix flake check --print-build-logs; then
 				handle_update_check_fail "$inp"
 				continue
 			fi
+		else
+			msg "No change in input, skipping checks."
+		fi
 
 		if ! git checkout "${ci_branch}"; then
 			handle_co_fail "${ci_branch}"