Draft: Fix compilation failure — bindings are currently unusable

I've done several things to fix the current failure to build:

• Updated soup3-rs Git URL (https://github.com/vhdirk/soup3-rs → https://gitlab.gnome.org/World/Rust/soup3-rs)
• Corrected package names for dependencies in the -sys crates
• Use more current .GIR files from my own repository—I hope that the primary repository adds the relevant files (by specifying them in dl.py) so that they too will be automatically maintained by the GitHub workflow
• Set the following to manual: WebKit2.InputMethodContext.filter_key_event, WebKit2.WebsiteDataManager.set_network_proxy_settings

In addition, I've added the v2_32, v2_34, and v2_36 features.

Several things are currently not working at all, but projects that depend on this are once-again compiling and mostly functioning as usual.