- Work around Dioxus 0.7.9 leaking getrandom_backend=wasm_js cfg into
the musl server build by disabling DX's auto flag and setting it only
for wasm32 in .cargo/config.toml.
- Split build-linux into @client and @server steps so the server build
can explicitly enable the server feature and target
x86_64-unknown-linux-musl.
- Configure the musl linker to use x86_64-linux-musl-gcc.