add package declaration for haskell-language-server in config.yaml

Author: soulomoon

bench/config.yaml

@@ -80,6 +80,7 @@ examples:
   # Small but heavily multi-component example
   # Disabled as it is far to slow. hie-bios >0.7.2 should help
   - name: haskell-language-server
+    package: haskell-language-server
     version: 2.9.0.0
     modules:
           - ghcide/session-loader/Development/IDE/Session.hs