### 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_
import logging
import os
import platform
import socket
import subprocess
import tempfile
import time
import warnings
from typing import Any, Dict, List, Mapping, Optional, Tuple, TypeVar, Union
from localstack import constants
from localstack.constants import (
    DEFAULT_BUCKET_MARKER_LOCAL,
    DEFAULT_DEVELOP_PORT,
    DEFAULT_VOLUME_DIR,
    ENV_INTERNAL_TEST_COLLECT_METRIC,
    ENV_INTERNAL_TEST_RUN,
    FALSE_STRINGS,
    LOCALHOST,
    LOCALHOST_IP,
    LOCALSTACK_ROOT_FOLDER,
    LOG_LEVELS,
    TRACE_LOG_LEVELS,
    TRUE_STRINGS,