move shell command back to top of file (#153)

Author: nmwsharp

install_env.sh

@@ -1,3 +1,5 @@
+#!/bin/bash
+
 # SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 #
@@ -13,7 +15,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-#!/bin/bash
 
 # Exit on error
 set -e