ty: use jemalloc from Nixpkgs (#517400)

pkgs/by-name/ty/ty/package.nix

@@ -7,6 +7,9 @@
   # nativeBuildInputs
   installShellFiles,
 
+  # buildInputs
+  rust-jemalloc-sys,
+
   buildPackages,
   versionCheckHook,
   nix-update-script,
@@ -38,6 +41,7 @@ rustPlatform.buildRustPackage (finalAttrs: {
   cargoHash = "sha256-A/oJeFIY/+Pu9jYp3hwGwkSAXfF0VLTHKGP48wsnheo=";
 
   nativeBuildInputs = [ installShellFiles ];
+  buildInputs = [ rust-jemalloc-sys ];
 
   # `ty`'s tests use `insta-cmd`, which depends on the structure of the `target/` directory,
   # and also fails to find the environment variable `$CARGO_BIN_EXE_ty`, which leads to tests failing.