Distinguish between pyodide-build and pypa/build as build frontends when handling build verbosity

[agriyakhetarpal]

See #2605

cc: @AndrewAnnex

[agriyakhetarpal]

I don't think this is the right approach at the moment, and I should try another way. What I think happens here is that _get_verbosity_flags will get wrapped in get_build_frontend_extra_flags, which will be called at the time of Pyodide builds. However, the finalisation of the build frontend flags happens outside and before the pyodide build command is called, which means the PYODIDE environment variable is set during the wheel builds and not when cibuildwheel performs its own preparation for the build, which means that this will fail to remove the verbosity-related flags.