Remove built-in Nu support in favor of extension (#10570)

Release Notes:

- Removed built-in Nu language support in favor of an extension.

---------

Co-authored-by: Marshall <marshall@zed.dev>

Cargo.lock

@@ -5516,7 +5516,6 @@ dependencies = [
  "tree-sitter-jsdoc",
  "tree-sitter-json 0.20.0",
  "tree-sitter-markdown",
- "tree-sitter-nu",
  "tree-sitter-proto",
  "tree-sitter-python",
  "tree-sitter-regex",
@@ -10596,15 +10595,6 @@ dependencies = [
  "tree-sitter",
 ]
 
-[[package]]
-name = "tree-sitter-nu"
-version = "0.0.1"
-source = "git+https://github.com/nushell/tree-sitter-nu?rev=7dd29f9616822e5fc259f5b4ae6c4ded9a71a132#7dd29f9616822e5fc259f5b4ae6c4ded9a71a132"
-dependencies = [
- "cc",
- "tree-sitter",
-]
-
 [[package]]
 name = "tree-sitter-proto"
 version = "0.0.2"