### Summary

I know there is some ongoing work to mitigate these problems, but since I'm not aware which parts have already been addressed and which not, I want to share some common failures here which I've seen during the last days:

1. When running `ansible-test sanity --color -v --junit --coverage-check --changed --docker --base-branch origin/main --skip-test pylint --skip-test ansible-doc --skip-test validate-modules --allow-disabled` in CI, the Python 2.6 `import` test fails:
```
02:05 ERROR: Command "/root/ansible_collections/community/general/tests/output/.tmp/sanity/import/minimal-py26/bin/python /root/ansible/test/lib/ansible_test/_data/quiet_pip.py install --disable-pip-version-check coverage -c /root/ansible/test/lib/ansible_test/_data/requirements/constraints.txt" returned exit status 1.
02:05 >>> Standard Error
02:05 Could not find a version that satisfies the requirement coverage<5.0.0,>=4.5.1 (from -c /root/ansible/test/lib/ansible_test/_data/requirements/constraints.txt (line 2)) (from versions: )
02:05 No matching distribution found for coverage<5.0.0,>=4.5.1 (from -c /root/ansible/test/lib/ansible_test/_data/requirements/constraints.txt (line 2))
02:05 >>> Standard Output
02:05 Collecting coverage<5.0.0,>=4.5.1 (from -c /root/ansible/test/lib/ansible_test/_data/requirements/constraints.txt (line 2))
```
(See https://app.shippable.com/github/ansible-collections/community.general/runs/8257/1/console for the full log)

2. When running unit tests for Python 2.6 with `ansible-test units -v --color --docker --coverage` with `unittest2 ; python_version < '2.7'` in tests/unit/requirements.txt, it fails:
```
Run command: /usr/bin/python2.6 /root/ansible/test/lib/ansible_test/_data/quiet_pip.py install --disable-pip-version-check -r /root/ansible/test/lib/ansible_test/_data/requirements/units.txt -r tests/unit/requirements.txt coverage -c /root/ansible/test/lib/ansible_test/_data/requirements/constraints.txt
Collecting unittest2 (from -r tests/unit/requirements.txt (line 1))
  Could not find a version that satisfies the requirement unittest2 (from -r tests/unit/requirements.txt (line 1)) (from versions: )
No matching distribution found for unittest2 (from -r tests/unit/requirements.txt (line 1))
ERROR: Command "/usr/bin/python2.6 /root/ansible/test/lib/ansible_test/_data/quiet_pip.py install --disable-pip-version-check -r /root/ansible/test/lib/ansible_test/_data/requirements/units.txt -r tests/unit/requirements.txt coverage -c /root/ansible/test/lib/ansible_test/_data/requirements/constraints.txt" returned exit status 1.
```
(See https://github.com/ansible-collections/community.hrobot/runs/2264772861?check_suite_focus=true)


### Issue Type

Bug Report

### Component Name

ansible-test

### Ansible Version

```console (paste below)
devel
```


### Configuration

...

### OS / Environment

...

### Steps to Reproduce

...

### Expected Results

...

### Actual Results

...
if use_httptester:
                httptester_id = run_httptester(args)
            else:
                httptester_id = None
            test_options = [
                '--detach',
                '--volume', '/sys/fs/cgroup:/sys/fs/cgroup:ro',
                '--privileged=%s' % str(privileged).lower(),
            ]
            if args.docker_memory:
                test_options.extend([
                    '--memory=%d' % args.docker_memory,
                    '--memory-swap=%d' % args.docker_memory,
                ])
            docker_socket = '/var/run/docker.sock'
            if args.docker_seccomp != 'default':
                test_options += ['--security-opt', 'seccomp=%s' % args.docker_seccomp]
            if get_docker_hostname() != 'localhost' or os.path.exists(docker_socket):
                test_options += ['--volume', '%s:%s' % (docker_socket, docker_socket)]
            if httptester_id:
                test_options += ['--env', 'HTTPTESTER=1', '--env', 'KRB5_PASSWORD=%s' % args.httptester_krb5_password]
                network = get_docker_preferred_network_name(args)
                if not is_docker_user_defined_network(network):
                    
                    for host in HTTPTESTER_HOSTS:
                        test_options += ['--link', '%s:%s' % (httptester_id, host)]
            if isinstance(args, IntegrationConfig):
                cloud_platforms = get_cloud_providers(args)
                for cloud_platform in cloud_platforms:
                    test_options += cloud_platform.get_docker_run_options()