Fix check_cookiecutter.sh hashbang

This was broken by commit 436eea4
(#375) adding an
SPDX-License-Identifier commit on line 1.

Author: ednolan

cookiecutter/check_cookiecutter.sh

@@ -1,5 +1,5 @@
-# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 #!/usr/bin/env bash
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 set -euo pipefail