Tests should not do requests to updates.drupal.org

Problem/Motivation

In #3074993-31: Use "current" in update URLs instead of CORE_COMPATIBILITY to retrieve all future updates → it became clear that our tests that extend \Drupal\FunctionalTests\Update\UpdatePathTestBase and some other tests make real calls out to updates.drupal.org that fetch XML. These test aren't actually meant to test this XML request. They just happen to make it.

If the requests aren't successful the tests don't fail because the test aren't asserting anything about the responses. If the requests are successful but the XML isn't in an expected format the test will fail.

So basically we are inadvertently testing the format of live XML on updates.drupal.org and these requests may be slowing down our test suite.

Proposed resolution

Make sure we aren't making calls to updates.drupal.org.

All tests that extend UpdatePathTestBase or otherwise would trigger requests to updates.drupal.org should actually be calling something like \Drupal\Tests\update\Functional\UpdateTestBase::refreshUpdateStatus() to change the update URL so we aren't making real requests to updates.drupal.org

Remaining tasks

all

User interface changes

API changes

Data model changes

Release notes snippet