cargoSetupHook: set crt-static

Tell rust if we want our binaries linked statically or dynamically.
Otherwise the compiler will always produce statically linked binaries for musl
targets, as this is the default.

pkgs/build-support/rust/hooks/default.nix

@@ -76,6 +76,7 @@ in {
             [target."${shortTarget}"]
             "linker" = "${ccForHost}"
           ''}
+          "rustflags" = [ "-C", "target-feature=${if stdenv.hostPlatform.isStatic then "+" else "-"}crt-static" ]
         '';
       };
     } ./cargo-setup-hook.sh) {};