Extract TOML support into an extension (#9940)

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

There's a small workaround necessary in order for us to set the file
permissions on the `taplo` binary so that it can be run. Eventually
we'll want to build this into the extension API, but for now we're just
hard-coding it on the host side.

Release Notes:

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

crates/extensions_ui/src/extension_suggest.rs

@@ -46,6 +46,8 @@ pub fn suggested_extension(file_extension_or_name: &str) -> Option<Arc<str>> {
                 ("sql", "sql"),
                 ("svelte", "svelte"),
                 ("swift", "swift"),
+                ("toml", "Cargo.lock"),
+                ("toml", "toml"),
                 ("templ", "templ"),
                 ("wgsl", "wgsl"),
                 ("zig", "zig"),