fix(ci): actually only run tests on non-docs changes (gatsbyjs#10287)

Previously, this was mostly working (see
gatsbyjs#9889 where the unit tests are
not run, but the e2e tests are run), but as is evident, the e2e tests
are still run.

This is because the "merging" of template inclusions doesn't work quite
like we'd expect, so need to iron that out. This should iron it out!

.circleci/config.yml

@@ -58,8 +58,12 @@ aliases:
       - run: yarn jest -w 1
 
   e2e-test-workflow: &e2e-test-workflow
-    <<: *ignore_master
-    <<: *ignore_docs
+    filters:
+      branches:
+        ignore:
+          - master
+          - /docs.+/
+          - /blog.+/
     requires:
       - bootstrap