| Fix Action Text system tests leaving Chrome offline and leaking RACK_ENV (#59082)
* Restore Chrome's network in Action Text system tests
`while_offline` used `Object#with` to restore the saved network
conditions, passing Chrome's string-keyed hash back to
`network_conditions=`, which adds symbol-keyed defaults. json 3.0
raises `JSON::GeneratorError` on the duplicate keys, so after the
offline upload test Chrome stayed offline and every later system test
failed with `net::ERR_INTERNET_DISCONNECTED`.
Set the conditions with symbol keys and reset to online in an `ensure`.
* Set RACK_ENV before Action Text system tests boot Puma
When `RACK_ENV` was unset, Puma set it as Capybara booted the server,
so the first system test in the run failed `LeakChecker` with
"Environment leak detected". |