- cwconfig, doc/admin/setup: docstring adjustment wrt 3.9 & virtualenv

- testing/rst: windmill (which is gone from the testing infrastructure)

- other docs: "stuff introduced in 3.9" cleanup, as we don't care
  about the version old features were introduced

- server/hooky.py: bw compat for propagation hooks

- server/schemaserial.py: pre CWUniqueTogetherConstraint migration support

- web.__init__.py: dumps bw import

- autoform.py: .action ppty is gone, also deprecate set_action and get_action

- baseviews: CSVView.subvid gone long ago, secondary view removal

- primary.py: _render_attribute & _render_relation signature change

- reledit.py: rvid/default_value bw compat, should_edit_* dropped

- webconfig.py: resourcefile is gone

- formfields.py: old vocabulary handling

- request.py: build_ajax_replace_url, external_resource


Related to #2782004.