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]`
return "%s:%s" % (self.region, self.prefix)
PREDEFINED_ENVIRONMENTS = {ENV_DEV: Environment(region=REGION_LOCAL, prefix=ENV_DEV)}
def get_environment(env=None, region_name=None):
    """
    Return an Environment object based on the input arguments.
    Parameter `env` can be either of:
        * None (or empty), in which case the rules below are applied to (env = os.environ['ENV'] or ENV_DEV)
        * an Environment object (then this object is returned)
        * a string '<region>:<name>', which corresponds to Environment(region='<region>', prefix='<prefix>')
        * the predefined string 'dev' (ENV_DEV), which implies Environment(region='local', prefix='dev')
        * a string '<name>', which implies Environment(region=DEFAULT_REGION, prefix='<name>')
    Additionally, parameter `region_name` can be used to override DEFAULT_REGION.
    """
    if not env:
        if "ENV" in os.environ:
            env = os.environ["ENV"]
        else:
            env = ENV_DEV
    elif not is_string(env) and not isinstance(env, Environment):
        raise Exception("Invalid environment: %s" % env)
    if is_string(env):
        env = Environment.from_string(env)
    if region_name:
        env.region = region_name
    if not env.region:
        raise Exception('Invalid region in environment: "%s"' % env)
    return env
def is_local_env(env):
    return not env or env.region == REGION_LOCAL or env.prefix == ENV_DEV
class Boto3Session(boto3.session.Session):