Improve performance of JSON schema creation (#6770)

JSON LSP adapter now caches the schema. `workspace_configuration` is
back to being async, and we are also no longer asking for font names
twice while constructing the schema.
Release Notes:
- Improved performance when opening the .json files.

---------

Co-authored-by: Kirill <kirill@zed.dev>

crates/project/src/project.rs

@@ -2714,13 +2714,12 @@ impl Project {
                 })?;
 
                 for (adapter, server) in servers {
-                    let workspace_config =
+                    let settings =
                         cx.update(|cx| adapter.workspace_configuration(server.root_path(), cx))?;
+
                     server
                         .notify::<lsp::notification::DidChangeConfiguration>(
-                            lsp::DidChangeConfigurationParams {
-                                settings: workspace_config.clone(),
-                            },
+                            lsp::DidChangeConfigurationParams { settings },
                         )
                         .ok();
                 }