Our bundled binaries seem to have been not working for some time.

We had two separate issues:
- The `av` dependency (via `aiortc`) wasn't being properly discovered
  by PyInstaller.
  This has been fixed with a hook.
- On Linux stripping of the libraries apparently causes some corruption
  See: pypa/manylinux#119
  Therefore stripping is disabled for now.
- The gevent runtime hook would attempt to start the aio event loop. 
  This caused a warning about an already running loop.

This also fixes:
- Don't include unnecessary av libraries in the bundle
- Remove no longer used GETH_URL and SOLC_URL build args from the
  `bundle-docker` make target.
- On CI: Invoke the built binaries with `--help` as a minimal
  functionality sanity check.