https://github.com/localstack/localstack/blob/e7efc768a20e75feafe3702a5a6e477a233feff2/localstack/utils/aws/aws_stack.py#L904

```
File "/usr/local/lib/python3.8/site-packages/localstack/services/generic_proxy.py", line 50, in <module>
from localstack.utils.aws import aws_stack
File "/usr/local/lib/python3.8/site-packages/localstack/utils/aws/aws_stack.py", line 904, in <module>
) -> dict[str, str]:
TypeError: 'type' object is not subscriptable
```

Please fix to `Dict[str, str]`
"""Fix the account ID in the ARNs returned in the given Flask response or string"""
    existing = existing or ["123456789", "1234567890", "123456789012", get_aws_account_id()]
    existing = existing if isinstance(existing, list) else [existing]
    replace = replace or get_aws_account_id()
    is_str_obj = is_string_or_bytes(response)
    content = to_str(response if is_str_obj else response._content)
    replace = r"arn{col}aws{col}\1{col}\2{col}{acc}{col}".format(col=colon_delimiter, acc=replace)
    for acc_id in existing:
        regex = r"arn{col}aws{col}([^:%]+){col}([^:%]*){col}{acc}{col}".format(
            col=colon_delimiter, acc=acc_id
        )
        content = re.sub(regex, replace, content)
    if not is_str_obj:
        response._content = content
        response.headers["Content-Length"] = len(response._content)
        return response
    return content
def inject_test_credentials_into_env(env):
    if ENV_ACCESS_KEY not in env and ENV_SECRET_KEY not in env:
        env[ENV_ACCESS_KEY] = "test"
        env[ENV_SECRET_KEY] = "test"
def inject_region_into_env(env, region):