conda: put `noarch: python` on correct artiq-board package.

Fixes #989.

conda/artiq-board/meta.yaml

@@ -16,9 +16,9 @@ build:
 
 outputs:
   - name: artiq-{{ environ["ARTIQ_TARGET"] }}-{{ environ["ARTIQ_VARIANT"] }}
-    noarch: generic
+    noarch: python
     files:
-      - lib
+      - site-packages
     requirements:
       run:
         - artiq {{ "{tag} py_{number}+git{hash}".format(tag=environ["GIT_DESCRIBE_TAG"], number=environ["GIT_DESCRIBE_NUMBER"], hash=environ["GIT_FULL_HASH"][:8]) }}