lsp: Identify language servers by their configuration (#35270)

- **WIP: reorganize dispositions**
- **Introduce a LocalToolchainStore trait and use it for LspAdapter
methods**

Closes #35782
Closes #27331

Release Notes:

- Python: Improved propagation of a selected virtual environment into
the LSP configuration. This should the make all language-related
features such as Go to definition or Find all references more reliable.

---------

Co-authored-by: Cole Miller <cole@zed.dev>
Co-authored-by: Lukas Wirth <lukas@zed.dev>

crates/remote_server/src/headless_project.rs

@@ -171,7 +171,11 @@ impl HeadlessProject {
                 buffer_store.clone(),
                 worktree_store.clone(),
                 prettier_store.clone(),
-                toolchain_store.clone(),
+                toolchain_store
+                    .read(cx)
+                    .as_local_store()
+                    .expect("Toolchain store to be local")
+                    .clone(),
                 environment,
                 manifest_tree,
                 languages.clone(),