Dumb question just want to confirm if im correct

If I have a Cisco 5506 ASA with an Aruba 2930 L3 switch

Network: 172.25.43.0/24

Firewall IP: 172.25.43.1

Switch: 172.25.43.254

If get the switch to DHCP/routing instead of the firewall and I want it to be just a FLAT network and created a VLAN of 172.25.43.0 in the switch.

On the firewall I don't have to do any routing for 172.25.43.0 correct?

Like if I created VLAN 20 in the switch 172.25.20.0/24

On the firewall I would have to route 172.25.20.0 255.255.255.0 172.25.43.254

Or would I have to put the firewall and switch into a different network? IE firewall: 172.25.44.1 Switch 172.25.44.254 and then create the VLAN of 172.25.43.0 and then set the route on the firewall 172.25.43.0 255.255.255.0 to 172.25.43.254

Sorry (not a networking expert) (I would just test it myself but not in the office today and this question is eating at me haha)