Adopt generic `check` job that summarizes test results

[Sviatoslav Sydorenko (Святослав Сидоренко)]

In order to lower the maintenance of list of required jobs on each repository, we would like to propose introduction of a summary-job named check that depends on other jobs from the same workflow.

This mimics how zuul check stage works and will allow use to reduce the number of jobs we need to manually set as required in repository settings.

It should be noted that checks performed by bots, other systems or other workflows still need to be manually marked as required. For example we likely still want to list ack and pre-commit.ci as required.

Example: ansible/vscode-ansible#272.