use enabledApiProposals instead of wildcard property, also update compilation units to only include d.ts-files that are needed, https://github.com/microsoft/vscode/issues/131165

extensions/css-language-features/package.json

@@ -17,7 +17,6 @@
   ],
   "main": "./client/out/node/cssClientMain",
   "browser": "./client/dist/browser/cssClientMain",
-  "enableProposedApi": true,
   "capabilities": {
     "virtualWorkspaces": true,
     "untrustedWorkspaces": {