### 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_
DISABLE_CORS_HEADERS = is_env_true("DISABLE_CORS_HEADERS")
DISABLE_CORS_CHECKS = is_env_true("DISABLE_CORS_CHECKS")
DISABLE_CUSTOM_CORS_S3 = is_env_true("DISABLE_CUSTOM_CORS_S3")
DISABLE_CUSTOM_CORS_APIGATEWAY = is_env_true("DISABLE_CUSTOM_CORS_APIGATEWAY")
EXTRA_CORS_ALLOWED_HEADERS = os.environ.get("EXTRA_CORS_ALLOWED_HEADERS", "").strip()
EXTRA_CORS_EXPOSE_HEADERS = os.environ.get("EXTRA_CORS_EXPOSE_HEADERS", "").strip()
EXTRA_CORS_ALLOWED_ORIGINS = os.environ.get("EXTRA_CORS_ALLOWED_ORIGINS", "").strip()
DISABLE_PREFLIGHT_PROCESSING = is_env_true("DISABLE_PREFLIGHT_PROCESSING")
DISABLE_EVENTS = is_env_true("DISABLE_EVENTS")
DEBUG_ANALYTICS = is_env_true("DEBUG_ANALYTICS")
DEBUG_HANDLER_CHAIN = is_env_true("DEBUG_HANDLER_CHAIN")
EAGER_SERVICE_LOADING = is_env_true("EAGER_SERVICE_LOADING")
STRICT_SERVICE_LOADING = is_env_not_false("STRICT_SERVICE_LOADING")
SKIP_INFRA_DOWNLOADS = os.environ.get("SKIP_INFRA_DOWNLOADS", "").strip()
SKIP_SSL_CERT_DOWNLOAD = is_env_true("SKIP_SSL_CERT_DOWNLOAD")
CUSTOM_SSL_CERT_PATH = os.environ.get("CUSTOM_SSL_CERT_PATH", "").strip()
ALLOW_NONSTANDARD_REGIONS = is_env_true("ALLOW_NONSTANDARD_REGIONS")
if ALLOW_NONSTANDARD_REGIONS:
    os.environ["MOTO_ALLOW_NONEXISTENT_REGION"] = "true"
MAIN_CONTAINER_NAME = os.environ.get("MAIN_CONTAINER_NAME", "").strip() or "localstack-main"
LOCALSTACK_BUILD_GIT_HASH = os.environ.get("LOCALSTACK_BUILD_GIT_HASH", "").strip() or None
LOCALSTACK_BUILD_DATE = os.environ.get("LOCALSTACK_BUILD_DATE", "").strip() or None
OUTBOUND_HTTP_PROXY = os.environ.get("OUTBOUND_HTTP_PROXY", "")
OUTBOUND_HTTPS_PROXY = os.environ.get("OUTBOUND_HTTPS_PROXY", "")
ARN_PARTITION_REWRITING = is_env_true("ARN_PARTITION_REWRITING")
ARN_PARTITION_FALLBACK = os.environ.get("ARN_PARTITION_FALLBACK", "") or "aws"
FORCE_SHUTDOWN = is_env_not_false("FORCE_SHUTDOWN")
no_proxy = ",".join([constants.LOCALHOST_HOSTNAME, LOCALHOST, LOCALHOST_IP, "[::1]"])
if os.environ.get("no_proxy"):
    os.environ["no_proxy"] += "," + no_proxy