fix: use /usr/bin/env shebang in skeleton.bash

Replace `#!/bin/bash` by `#!/usr/bin/env bash` since `bash` binary is not always in `/bin`.

Signed-off-by: Pierre-Yves Landuré <[email protected]>

Author: landure

skeleton.bash

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # @file skeleton.bash
 # @author Pierre-Yves Landuré < contact at biapy dot fr >
 # @brief Bash script skeleton.