Extract Erlang support into an extension (#9974)

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

Tested using a Nix shell:

```
nix-shell -p erlang-ls
```

Release Notes:

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

Cargo.lock

@@ -5455,7 +5455,6 @@ dependencies = [
  "tree-sitter-elixir",
  "tree-sitter-elm",
  "tree-sitter-embedded-template",
- "tree-sitter-erlang",
  "tree-sitter-glsl",
  "tree-sitter-go",
  "tree-sitter-gomod",
@@ -10440,16 +10439,6 @@ dependencies = [
  "tree-sitter",
 ]
 
-[[package]]
-name = "tree-sitter-erlang"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "93ced5145ebb17f83243bf055b74e108da7cc129e12faab4166df03f59b287f4"
-dependencies = [
- "cc",
- "tree-sitter",
-]
-
 [[package]]
 name = "tree-sitter-glsl"
 version = "0.1.4"
@@ -12677,6 +12666,13 @@ dependencies = [
  "zed_extension_api 0.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "zed_erlang"
+version = "0.0.1"
+dependencies = [
+ "zed_extension_api 0.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "zed_extension_api"
 version = "0.0.4"