### Is there an existing issue for this?

- [X] I have searched the existing issues

### Feature description

I prefer not to use the real regions when doing tests or local stuff to make sure that if it accidentally picks up real credentials, it won't actually create or interact with resources in AWS. This used to work find in localstack - I even dug through the code to find that there is an option in the `RegionStore` to disable validation of the region string. At some point, you removed any way to disable that validation though, which means it just fails all requests using a custom region.

### 🧑‍💻 Implementation

There's already a flag that is passed to the account and region store constructors to disable validation. Seems like an environment variable or configuration flag to disable validation could be propagated.

### Anything else?

_No response_
"THUNDRA_AGENT_PYTHON_VERSION",
    "USE_SINGLE_REGION",
    "USE_SSL",
    "WAIT_FOR_DEBUGGER",
    "WINDOWS_DOCKER_MOUNT_PREFIX",
]
def is_local_test_mode() -> bool:
    """Returns True if we are running in the context of our local integration tests."""
    return is_env_true(ENV_INTERNAL_TEST_RUN)
def is_collect_metrics_mode() -> bool:
    """Returns True if metric collection is enabled."""
    return is_env_true(ENV_INTERNAL_TEST_COLLECT_METRIC)
def collect_config_items() -> List[Tuple[str, Any]]:
    """Returns a list of key-value tuples of LocalStack configuration values."""
    none = object()  
    
    keys = []
    keys.extend(CONFIG_ENV_VARS)
    keys.append("DATA_DIR")
    keys.sort()
    values = globals()
    result = []
    for k in keys:
        v = values.get(k, none)
        if v is none:
            continue
        result.append((k, v))
    result.sort()
    return result
def parse_service_ports() -> Dict[str, int]: