chore: removing unused reference to gh-pages branch from circle conf

whenever we push (automatically) to `gh-pages`, we get a build failure.
this piece of configuration is unused, as it's not even in the `gh-pages` branch.

Author: Shesekino

.circleci/config.yml

@@ -363,8 +363,3 @@ workflows:
             branches:
               only:
                 - master
-
-general:
-  branches:
-    ignore:
-      - gh-pages