shell: stop fish from having to be built every time

Drop the patch to fish source code, instead opting
to employ fish's inbuilt share/fish/vendor_conf.d
to add custom code to fish.

This is both a bit simpler, and makes it so fish does not
have to be compiled on every update to it's source / to my configuration.

packages/shell/fishinit.nix

@@ -1,9 +1,11 @@
 {
   pkgs,
   aliasesStr,
+  vendorConf,
 }:
-pkgs.writeText "config.fish" ''
-
+pkgs.writeTextDir "${vendorConf}/blox_config.fish"
+# fish
+''
   # source ${pkgs.fishPlugins.sponge}/share/zsh-defer/zsh-defer.plugin.zsh
   ${pkgs.atuin}/bin/atuin init fish | source
   ${pkgs.zoxide}/bin/zoxide init fish | source
@@ -11,6 +13,10 @@ pkgs.writeText "config.fish" ''
   ${pkgs.direnv}/bin/direnv hook fish | source
   ${pkgs.pay-respects}/bin/pay-respects fish --alias f --nocnf | source
 
+  # I need to source /etc/profile using foreign-env, to get stuff set by nixos, e.g. environment.systemVariables.
+  # set -p fish_function_path ${pkgs.fishPlugins.foreign-env}/share/fish/vendor_functions.d
+
+  # fenv source /etc/profile
 
   source ${./config.fish}