CI: Ignore all API/UI test code for Python 2 lint

We always run them with Python 3

setup.cfg

@@ -4,5 +4,5 @@ import-order-style=smarkets
 strictness=short
 docstring_style=sphinx
 max-line-length=127
-exclude=__init__.py,tools,tests/env/
+exclude=__init__.py,tools,tests
 application-import-names=avu_json,conftest,util,api,config,constants,data_access_token,datacite,datarequest,data_object,epic,error,folder,groups,groups_import,intake,intake_dataset,intake_lock,intake_scan,intake_utils,intake_vault,json_datacite,json_landing_page,jsonutil,log,mail,meta,meta_form,msi,notifications,schema,schema_transformation,schema_transformations,settings,pathutil,provenance,policies_intake,policies_datamanager,policies_datapackage_status,policies_folder_status,policies_datarequest_status,publication,query,replication,revisions,revision_strategies,revision_utils,rule,user,vault,sram,arb_data_manager,cached_data_manager,resource,yoda_names,policies_utils