### 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

...
))
        playbook = json.dumps([play], indent=4, sort_keys=True)
        with named_temporary_file(args=args, directory=test_env.integration_dir, prefix='%s-' % target.name, suffix='.yml', content=playbook) as playbook_path:
            filename = os.path.basename(playbook_path)
            display.info('>>> Playbook: %s\n%s' % (filename, playbook.strip()), verbosity=3)
            cmd = ['ansible-playbook', filename, '-i', os.path.relpath(test_env.inventory_path, test_env.integration_dir)]
            if start_at_task:
                cmd += ['--start-at-task', start_at_task]
            if args.tags:
                cmd += ['--tags', args.tags]
            if args.skip_tags:
                cmd += ['--skip-tags', args.skip_tags]
            if args.diff:
                cmd += ['--diff']
            if isinstance(args, NetworkIntegrationConfig):
                if args.testcase:
                    cmd += ['-e', 'testcase=%s' % args.testcase]
            if args.verbosity:
                cmd.append('-' + ('v' * args.verbosity))
            env = integration_environment(args, target, test_dir, test_env.inventory_path, test_env.ansible_config, env_config)
            cwd = test_env.integration_dir
            env.update(dict(
                
                ANSIBLE_PLAYBOOK_DIR=cwd,
            ))
            env['ANSIBLE_ROLES_PATH'] = test_env.targets_dir
            module_coverage = 'non_local/' not in target.aliases
            intercept_command(args, cmd, target_name=target.name, env=env, cwd=cwd, temp_path=temp_path,
                              remote_temp_path=remote_temp_path, module_coverage=module_coverage)
def get_changes_filter(args):