WIP: Use cargo check for on-disk diagnostics

Co-Authored-By: Nathan Sobo <nathan@zed.dev>
Co-Authored-By: Max Brunsfeld <max@zed.dev>

crates/lsp/src/lsp.rs

@@ -226,7 +226,11 @@ impl LanguageServer {
             process_id: Default::default(),
             root_path: Default::default(),
             root_uri: Some(root_uri),
-            initialization_options: Default::default(),
+            initialization_options: Some(json!({
+                "checkOnSave": {
+                    "enable": false
+                },
+            })),
             capabilities: lsp_types::ClientCapabilities {
                 experimental: Some(json!({
                     "serverStatusNotification": true,