Error building px4_fmu-v5

I (re-)installed the Arm GNU toolchain (using these instructions as I am running WSL2 with Ubuntu 22.04).

Here you mention that you are running 22.04, but the link you sent which you based your container on, states that it supports the ROS 2 Rolling environment, which according to this link, does not support 22.04 Rolling Ridley (rolling) — ROS 2 Documentation: Foxy documentation.