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/languages/src/css.rs

@@ -2,7 +2,7 @@ use anyhow::{Context as _, Result};
 use async_trait::async_trait;
 use futures::StreamExt;
 use gpui::AsyncApp;
-use language::{LanguageToolchainStore, LspAdapter, LspAdapterDelegate};
+use language::{LspAdapter, LspAdapterDelegate, Toolchain};
 use lsp::{LanguageServerBinary, LanguageServerName};
 use node_runtime::{NodeRuntime, VersionStrategy};
 use project::{Fs, lsp_store::language_server_settings};
@@ -43,7 +43,7 @@ impl LspAdapter for CssLspAdapter {
     async fn check_if_user_installed(
         &self,
         delegate: &dyn LspAdapterDelegate,
-        _: Arc<dyn LanguageToolchainStore>,
+        _: Option<Toolchain>,
         _: &AsyncApp,
     ) -> Option<LanguageServerBinary> {
         let path = delegate
@@ -144,7 +144,7 @@ impl LspAdapter for CssLspAdapter {
         self: Arc<Self>,
         _: &dyn Fs,
         delegate: &Arc<dyn LspAdapterDelegate>,
-        _: Arc<dyn LanguageToolchainStore>,
+        _: Option<Toolchain>,
         cx: &mut AsyncApp,
     ) -> Result<serde_json::Value> {
         let mut default_config = json!({