In devstack, the public network is created without DHCP. Neutron has assigned an IP address to the instance, but there is no DHCP server that tells the instance what its IP is.

You can double-check this by checking the instance's console log openstack console log show. If it's a Cirros instance, it should tell you its IP address. Most likely, however, you will see how it tries to acquire an IP address and gives up after a while. If it's not Cirros, and if the console log is not conclusive, open an interactive console using the URL in openstack console url show and check the IP settings. In the interactive console, you can also set the IP address manually and check if the instance is accessible this way.

Of course, you also need to open ICMP in the instance's security group(s), as mentioned above.

I'm not sure about devstack, but a couple of things to check.

Is IP forwarding enabled on your host (10.105.67.113?)? I think it probably is because you can ping the 172. 24.4.1 address, but it might be worth checking.

Is ICMP included in any security groups associated with the instance?

OpenStack has allocated an IP address to the instance, but has the instance obtained/configured it? Can you check the port configuration for the instance? Is your image using cloud-init? Is your metadata service working correctly? Can you login to the console of the instance through horizon and check your interface?

No answers here directly I'm afraid, but that's where I'd start looking.