Fix shebang in ps1 scripts

Author: tspascoal

scripts/seed-database.ps1

@@ -1,4 +1,4 @@
-#!/bin/pwsh
+#!/usr/bin/env pwsh
 
 # Source common utilities
 . "$PSScriptRoot/common.ps1"

scripts/start-app.ps1

@@ -1,4 +1,5 @@
-# Source common utilities
+#!/usr/bin/env pwsh
+
 . "$PSScriptRoot/common.ps1"
 
 # Store initial directory