rustracer: 2.1.40 -> 2.1.44

NOTE: even though the latest upstream version is 2.1.46 we cannot use
this as every rustracer version technically requires nightly Rust. We
work around this by setting `RUSTC_BOOTSTRAP`, but also have to stick to
older versions where each used "nightly" feature is already in a `rustc`
that's also available in `nixpkgs`.

ZHF #122042
Closes #119155
Hydra build: https://hydra.nixos.org/build/142609369

pkgs/development/tools/rust/racer/default.nix

@@ -2,16 +2,16 @@
 
 rustPlatform.buildRustPackage rec {
   pname = "racer";
-  version = "2.1.40";
+  version = "2.1.44";
 
   src = fetchFromGitHub {
     owner = "racer-rust";
     repo = "racer";
     rev = "v${version}";
-    sha256 = "sha256-8Is+RBfcXKbGSFzYoolLHs30rxlNI//xVGEOhxP2TV8=";
+    sha256 = "sha256-EmxJg2QDpGZ5TbMy9y6P11LdMucBdvewkRewuUzccGM=";
   };
 
-  cargoSha256 = "sha256-iUomr9viCdZk4nV75/OP8vHtJpMbmy+pq1IbaA2lLmE=";
+  cargoSha256 = "sha256-kKQnpEashpIwrXubuZIpU+tzxFaUjr6jaVunYPqaHnM=";
 
   nativeBuildInputs = [ makeWrapper ];
   buildInputs = lib.optional stdenv.isDarwin Security;