Added license to Wasm example scripts (#12604)

### Summary
Added the license header to the bash scripts added in #12303.

### Test plan
N/A

Author: Conarnar

.ci/scripts/setup-emscripten.sh

@@ -1,3 +1,9 @@
+#!/bin/bash
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
 
 set -ex
 

examples/wasm/test_build_wasm.sh

@@ -1,3 +1,9 @@
+#!/bin/bash
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
 
 set -e