[BUG] Improve user authorization for creating assignment

[athiruma]

• QUADS version (rpm -qa | grep quads and/or quads --version):
• Python version:
• Operating System:

Describe the bug
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quads/src/quads/server/blueprints/schedules.py

Lines 87 to 92 in 8055b8d

	@schedule_bp.route("/", methods=["POST"])
	@check_access(["admin", "user"])
	def create_schedule() -> Response:
	data = request.get_json()
	hostname = data.get("hostname")
	cloud = data.get("cloud")

Both users and admins have the same authorization levels. This will cause users can create schedules on their own

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