Update .devcontainer/postCreateCommand.sh

Co-authored-by: rugk <rugk+git@posteo.de>

.devcontainer/postCreateCommand.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 composer install --no-dev --optimize-autoloader
 sudo chmod a+x "$(pwd)" && sudo rm -rf /var/www/html && sudo ln -s "$(pwd)" /var/www/html