fix: remove Rust toolchain from packages and update session variables in default.nix

home/default.nix

@@ -7,10 +7,6 @@
   home.homeDirectory = "/home/elars";
   home.stateVersion = "25.05";
 
-  home.sessionVariables = {
-    RUST_SRC_PATH = "${pkgs.rustPlatform.rustLibSrc}";
-  };
-
   home.pointerCursor = {
     name = "Bibata-Modern-Classic";
     package = pkgs.bibata-cursors;

packages.nix

@@ -117,9 +117,7 @@ with pkgs; {
     ghc
     cabal-install
     go
-    rustc
-    cargo
-    rust-analyzer
+    rustup
     gcc
     binutils
     libGL