### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

I pass `AWS_REGION=eu-central-1` to the localstack container in the environment section but it is overwritten with `us-east-1`.


### Expected Behavior

`AWS_REGION` should be `eu-central-1`

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

This is my localstack container in the docker compose file:

```
  mock-aws:
    image: localstack/localstack-pro:3.1
    ports:
      - "4566:4566"
    volumes:
      - type: bind
        source: ../integration-tests/aws
        target: /etc/localstack/init/ready.d
        read_only: true
      # Path to local Docker UNIX domain socket
      - "/var/run/docker.sock:/var/run/docker.sock"
    environment:
      - LS_LOG=debug
      - AWS_ACCESS_KEY_ID=test
      - AWS_SECRET_ACCESS_KEY=test
      - AWS_REGION=eu-central-1
      - LOCALSTACK_AUTH_TOKEN=${LOCALSTACK_AUTH_TOKEN:- }
      - EMAIL_SENDER_ADDRESS=noreply@host.com

```

I mount a folder which contains bash script to be run to initialize the localstack services.
Here is for example the content of `integration-tests/aws/ses.sh`:

```
#!/bin/bash

awslocal ses verify-email-identity \
  --email-address ${EMAIL_SENDER_ADDRESS} \
  --region ${AWS_REGION}

awslocal ses list-identities \
  --region ${AWS_REGION}

```

The script is executed but `AWS_REGION` seems to be overwritten and now has the value `us-east-1`.
Please note that the other variable called `EMAIL_SENDER_ADDRESS` has the proper value.

See output:
```
local-dev-mock-aws-1  | + awslocal ses verify-email-identity --email-address noreply@hosy.com --region us-east-1
local-dev-mock-aws-1  | 2024-02-13T14:17:04.827  INFO --- [   asgi_gw_1] localstack.request.aws     : AWS ses.VerifyEmailIdentity => 200
local-dev-mock-aws-1  | + awslocal ses list-identities --region us-east-1
local-dev-mock-aws-1  | 2024-02-13T14:17:06.026  INFO --- [   asgi_gw_0] localstack.request.aws     : AWS ses.ListIdentities => 200
local-dev-mock-aws-1  | 2024-02-13T14:17:06.165  INFO --- [   asgi_gw_1] localstack.request.aws     : AWS ses.ListIdentities => 200
local-dev-mock-aws-1  | {
local-dev-mock-aws-1  |     "Identities": [
local-dev-mock-aws-1  |         "noreply@host.com"
local-dev-mock-aws-1  |     ]
local-dev-mock-aws-1  | }
```

This was working with localstack version `2.1.0`

### Environment

```markdown
- OS: Ubuntu 22.04.3 LTS
- LocalStack: 3.1.0
```


### Anything else?

_No response_
return self._provider_config.get(service, self.default_value)
    def set_provider_if_not_exists(self, service: str, provider: str) -> None:
        if service not in self._provider_config:
            self._provider_config[service] = provider
    def set_provider(self, service: str, provider: str):
        self._provider_config[service] = provider
    def bulk_set_provider_if_not_exists(self, services: List[str], provider: str):
        for service in services:
            self.set_provider_if_not_exists(service, provider)
    def __getitem__(self, item):
        return self.get_provider(item)
    def __setitem__(self, key, value):
        self.set_provider(key, value)
    def __len__(self):
        return len(self._provider_config)
    def __iter__(self):
        return self._provider_config.__iter__()
SERVICE_PROVIDER_CONFIG = ServiceProviderConfig("default")
SERVICE_PROVIDER_CONFIG.load_from_environment()
def init_directories() -> Directories:
    if is_in_docker:
        return Directories.for_container()
    else:
        if is_env_true("LOCALSTACK_CLI"):
            return Directories.for_cli()
        return Directories.for_host()
dirs: Directories
dirs = init_directories()