Extract Ruby extension (#11360)

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

As part of this, the new extension is prepared for adding support for
the `Ruby LSP` which has some blockers. See
https://github.com/zed-industries/zed/pull/8613 I was thinking of adding
an initial support for Ruby LSP but I think it would be better to start
with extracting the Ruby extension for now.

The implementation, as the 1st step, matches the bundled version but
with 3 differences:

1. Added signature output to the completion popup. See my comment below.
![CleanShot 2024-05-04 at 09 17
37@2x](https://github.com/zed-industries/zed/assets/1894248/486b7a48-ea0c-44ce-b0c9-9f8f5d3ad42d)

3. Use the shell environment for starting the `solargraph` executable.
See my comment below.
4. Bumped the tree sitter version for Ruby to the latest available
version.

Additionally, I plan to tweak this extension a bit in the future but I
think we should do this bit by bit. Thanks!

Release Notes:

- Removed built-in support for Ruby, in favor of making it available as
an extension.

---------

Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>

crates/languages/src/lib.rs

@@ -16,7 +16,6 @@ mod css;
 mod go;
 mod json;
 mod python;
-mod ruby;
 mod rust;
 mod tailwind;
 mod typescript;
@@ -50,7 +49,6 @@ pub fn init(
         ("proto", tree_sitter_proto::language()),
         ("python", tree_sitter_python::language()),
         ("regex", tree_sitter_regex::language()),
-        ("ruby", tree_sitter_ruby::language()),
         ("rust", tree_sitter_rust::language()),
         ("tsx", tree_sitter_typescript::language_tsx()),
         ("typescript", tree_sitter_typescript::language_typescript()),
@@ -156,8 +154,6 @@ pub fn init(
             node_runtime.clone(),
         ))]
     );
-    language!("ruby", vec![Arc::new(ruby::RubyLanguageServer)]);
-    language!("erb", vec![Arc::new(ruby::RubyLanguageServer),]);
     language!("regex");
     language!(
         "yaml",