Extract Clojure support into an extension (#10088)

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

Release Notes:

- Removed built-in support for Clojure, in favor of making it available
as an extension. The Clojure extension will be suggested for download
when you open a `.clj` or other Clojure-related files.

---------

Co-authored-by: Max <max@zed.dev>

crates/extensions_ui/src/extension_suggest.rs

@@ -16,6 +16,11 @@ fn suggested_extensions() -> &'static HashMap<&'static str, Arc<str>> {
         [
             ("astro", "astro"),
             ("beancount", "beancount"),
+            ("clojure", "bb"),
+            ("clojure", "clj"),
+            ("clojure", "cljc"),
+            ("clojure", "cljs"),
+            ("clojure", "edn"),
             ("csharp", "cs"),
             ("dockerfile", "Dockerfile"),
             ("elisp", "el"),