Update tests in job 'install' to use 'f4pga build' instead of the shell wrappers

[umarcor]

In #2509, toolchain wrappers written in bash were moved from this repo to chipsalliance/f4pga. Apart from moving them, the installation procedure was changed. Now, they are installed as a Python package. As a result, the entrypoints and the actual shell scripts are located in different places. Two environment variables are required for the scripts to find tools (binaries) and assets:

https://github.com/SymbiFlow/f4pga-arch-defs/blob/b9177bcfa16a76e263e3c246f1d5a985c883f9b8/.github/ci/install.sh#L18-L23

Furthermore, in chipsalliance/f4pga#530, an alternative implementation was merged, which is written in Python only. Actually, both the deprecated shell wrappers and the f4pga build subcommand are installed at the same time.

We should update the tests executed in CI job 'install', to use f4pga build instead of calling the deprecated wrappers through makefiles.