gnu: Remove python2-attrs.

* gnu/packages/python-xyz.scm (python2-attrs): Delete variable.

gnu/packages/python-xyz.scm

@@ -19336,9 +19336,6 @@ JSON) codec.")
      protocols.")
     (license license:expat)))
 
-(define-public python2-attrs
-  (package-with-python2 python-attrs))
-
 (define-public python-attrs-bootstrap
   (package
     (inherit python-attrs)