build: speed up flake8 by ignoring test data (#1970)

flake8/flakeheaven is quite slow because it scans test data
directories also. This patch adds more directories to flake8 ignore so
that flake8/flakeheaven can run faster.

Author: aucampia

setup.cfg

@@ -10,7 +10,11 @@ exclude =
     .tox,
     var,
     .mypy_cache,
-    test/data/suites/,
+    test/data/suites/, # does not contain python
+    test/jsonld/1.1/, # does not contain python
+    test/jsonld/test-suite/, # does not contain python
+    test/data/variants/, # does not contain python
+    test/data/translate_algebra/, # does not contain python
     docs/rdf_terms.rst, # This file is causing an error on GitHub actions
 extend-ignore =
     # Disabled so that black can control line length.