### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When attempting to sign some document using Localstack KMS inside a lambda container (also running on localstack), the localstack KMS listener returns some unknown error.

The KMS key and lambda containers have been created from the same CDK app deploy, and I can see all the resources in the localstack web console.

The test application I'm using to prove this behaviour is available here:
https://github.com/LukaHedt/localstack_kms_test

Instructions to run are in the main Readme, and the `/localstack/Readme.md` file.

`aws-sdk` returns an unknown error, and the localstack docker logs that I receive are available here:
https://pastebin.com/58Z3fXi3

Have done an amount of testing and can confidently claim the following:
- Have tested on multiple machines with the same outcome
- Doesn’t make a difference if I specify an ARN or a KeyID in the signing request
- Downgrading localstack versions either didn’t make a difference, or I couldn’t actually deploy a localstack container with version 0.12.20 or lower.

### Expected Behavior

KMS Sign should return a signature for the given payload.

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

Test application demonstrating the current behaviour is available here:

https://github.com/LukaHedt/localstack_kms_test

Full instructions to run are in the `/localstack/Readme.md` file.


### Environment

```markdown
- OS: MacOS Monteray 12.3
- LocalStack: 0.14.0
```


### Anything else?

_No response_
self.table_definitions = {}
        self.table_properties = {}
class EventForwarder:
    @classmethod
    def forward_to_targets(cls, records: List[Dict], background: bool = True):
        def _forward(*args):
            
            records_to_kinesis = copy.deepcopy(records)
            cls.forward_to_kinesis_stream(records_to_kinesis)
            
            forward_records = cls.prepare_records_to_forward_to_ddb_stream(records)
            cls.forward_to_ddb_stream(forward_records)
            
            cls.forward_to_lambda(forward_records)
        if background:
            return start_worker_thread(_forward)
        _forward()
    @staticmethod
    def forward_to_lambda(records):
        for record in records:
            sources = lambda_api.get_event_sources(source_arn=record["eventSourceARN"])
            event = {"Records": [record]}
            for src in sources:
                if src.get("State") != "Enabled":
                    continue
                lambda_api.run_lambda(
                    func_arn=src["FunctionArn"],
                    event=event,
                    context={},