fix: guard against optional client capabilities (tailwindlabs#602)

for client like lsp-mode for emacs which doesn't have colorProvider,
server is failing to start, and according to the specification, the
capabilities here is all optional, so we should guard the nil situation.

Author: merrickluo

packages/tailwindcss-language-server/src/server.ts

@@ -1563,10 +1563,10 @@ class DocumentService {
 function supportsDynamicRegistration(connection: Connection, params: InitializeParams): boolean {
   return (
     connection.onInitialized &&
-    params.capabilities.textDocument.hover.dynamicRegistration &&
-    params.capabilities.textDocument.colorProvider.dynamicRegistration &&
-    params.capabilities.textDocument.codeAction.dynamicRegistration &&
-    params.capabilities.textDocument.completion.dynamicRegistration
+    params.capabilities.textDocument.hover?.dynamicRegistration &&
+    params.capabilities.textDocument.colorProvider?.dynamicRegistration &&
+    params.capabilities.textDocument.codeAction?.dynamicRegistration &&
+    params.capabilities.textDocument.completion?.dynamicRegistration
   )
 }