Extract Dockerfile extension (#9832)

This PR extracts Dockerfile support into an extension and removes the
built-in Dockerfile support from Zed.

There's already an existing [Dockerfile
extension](https://github.com/d1y/dockerfile.zed) that was just missing
language server support. Language server support is being added to that
extension in https://github.com/d1y/dockerfile.zed/pull/2.

Release Notes:

- Removed built-in support for Dockerfile, in favor of making it
available as an extension. The Dockerfile extension will be suggested
for download when you open a `Dockerfile`.

crates/languages/src/lib.rs

@@ -18,7 +18,6 @@ mod csharp;
 mod css;
 mod dart;
 mod deno;
-mod dockerfile;
 mod elixir;
 mod elm;
 mod erlang;
@@ -70,7 +69,6 @@ pub fn init(
         ("clojure", tree_sitter_clojure::language()),
         ("cpp", tree_sitter_cpp::language()),
         ("css", tree_sitter_css::language()),
-        ("dockerfile", tree_sitter_dockerfile::language()),
         ("elixir", tree_sitter_elixir::language()),
         ("elm", tree_sitter_elm::language()),
         (
@@ -190,13 +188,6 @@ pub fn init(
         ]
     );
 
-    language!(
-        "dockerfile",
-        vec![Arc::new(dockerfile::DockerfileLspAdapter::new(
-            node_runtime.clone(),
-        ))]
-    );
-
     match &ElixirSettings::get(None, cx).lsp {
         elixir::ElixirLspSetting::ElixirLs => {
             language!(