### 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_
OPENSEARCH_ENDPOINT_STRATEGY = "port"
OPENSEARCH_MULTI_CLUSTER = is_env_not_false("OPENSEARCH_MULTI_CLUSTER")
LEGACY_SNS_GCM_PUBLISHING = is_env_true("LEGACY_SNS_GCM_PUBLISHING")
MAIN_DOCKER_NETWORK = os.environ.get("MAIN_DOCKER_NETWORK", "") or LAMBDA_DOCKER_NETWORK
PARITY_AWS_ACCESS_KEY_ID = is_env_true("PARITY_AWS_ACCESS_KEY_ID")
CFN_VERBOSE_ERRORS = is_env_true("CFN_VERBOSE_ERRORS")
CFN_IGNORE_UNSUPPORTED_RESOURCE_TYPES = is_env_not_false("CFN_IGNORE_UNSUPPORTED_RESOURCE_TYPES")
CFN_RESOURCE_PROVIDER_OVERRIDES = os.environ.get("CFN_RESOURCE_PROVIDER_OVERRIDES", "{}")
DNS_ADDRESS = os.environ.get("DNS_ADDRESS") or "0.0.0.0"
DNS_PORT = int(os.environ.get("DNS_PORT", "53"))
DNS_NAME_PATTERNS_TO_RESOLVE_UPSTREAM = (
    os.environ.get("DNS_NAME_PATTERNS_TO_RESOLVE_UPSTREAM") or ""
).strip()
DNS_LOCAL_NAME_PATTERNS = (os.environ.get("DNS_LOCAL_NAME_PATTERNS") or "").strip()  
DNS_RESOLVE_IP = os.environ.get("DNS_RESOLVE_IP") or LOCALHOST_IP
DNS_SERVER = os.environ.get("DNS_SERVER")
DNS_VERIFICATION_DOMAIN = os.environ.get("DNS_VERIFICATION_DOMAIN") or "localstack.cloud"
def use_custom_dns():
    return str(DNS_ADDRESS) not in FALSE_STRINGS
S3_VIRTUAL_HOSTNAME = "s3.%s" % LOCALSTACK_HOST.host
S3_STATIC_WEBSITE_HOSTNAME = "s3-website.%s" % LOCALSTACK_HOST.host
BOTO_WAITER_DELAY = int(os.environ.get("BOTO_WAITER_DELAY") or "1")
BOTO_WAITER_MAX_ATTEMPTS = int(os.environ.get("BOTO_WAITER_MAX_ATTEMPTS") or "120")
DISABLE_CUSTOM_BOTO_WAITER_CONFIG = is_env_true("DISABLE_CUSTOM_BOTO_WAITER_CONFIG")
DISABLE_BOTO_RETRIES = is_env_true("DISABLE_BOTO_RETRIES")
CONFIG_ENV_VARS = [
    "ALLOW_NONSTANDARD_REGIONS",
    "BOTO_WAITER_DELAY",
    "BOTO_WAITER_MAX_ATTEMPTS",
    "BUCKET_MARKER_LOCAL",