build(nix): update flake to prevent build errors #28394

- Updates nixpkgs to source a necessary Tree-sitter version
- Updates to a new llvm version as the old one was removed from nixpkgs
- Properly moves `doCheck` from a regular param to an attribute option

contrib/flake.nix

@@ -88,9 +88,7 @@
 
         # for neovim developers, beware of the slow binary
         neovim-developer = let inherit (final.luaPackages) luacheck;
-        in (final.neovim-debug.override {
-          doCheck = final.stdenv.isLinux;
-        }).overrideAttrs (oa: {
+        in final.neovim-debug.overrideAttrs (oa: {
           cmakeFlags = oa.cmakeFlags ++ [
             "-DLUACHECK_PRG=${luacheck}/bin/luacheck"
             "-DENABLE_LTO=OFF"
@@ -99,6 +97,7 @@
             # https://clang.llvm.org/docs/AddressSanitizer.html#symbolizing-the-reports
             "-DENABLE_ASAN_UBSAN=ON"
           ];
+          doCheck = final.stdenv.isLinux;
         });
       };
     } // flake-utils.lib.eachDefaultSystem (system:
@@ -150,7 +149,7 @@
             shellHook = oa.shellHook + ''
               export NVIM_PYTHON_LOG_LEVEL=DEBUG
               export NVIM_LOG_FILE=/tmp/nvim.log
-              export ASAN_SYMBOLIZER_PATH=${pkgs.llvm_11}/bin/llvm-symbolizer
+              export ASAN_SYMBOLIZER_PATH=${pkgs.llvm_18}/bin/llvm-symbolizer
 
               # ASAN_OPTIONS=detect_leaks=1
               export ASAN_OPTIONS="log_path=./test.log:abort_on_error=1"