--allow-hosts does not account for dynamic DNS resolution at runtime

When using `--allow-hosts` to permit network connections to specific hostnames, `pytest-socket` resolves these hostnames to IP addresses at the start of the test session. However, libraries like `boto3` (which utilizes `urllib3`) perform DNS resolution at runtime, potentially obtaining different IP addresses. As a result, even if a hostname is specified in `--allow-hosts`, connections made to IP addresses resolved during test execution are blocked, leading to unexpected `SocketConnectBlockedError` exceptions. **Steps to Reproduce:** 1. Install `boto3`, `pytest`, and `pytest-socket`. 2. Write a test that uses `boto3` to interact with an AWS service (e.g., listing S3 buckets). 3. Run pytest with the following options: ```bash pytest --disable-socket --allow-hosts=amazonaws.com ``` 4. Observe that the test fails with a `SocketConnectBlockedError`, despite `amazonaws.com` being allowed. **Expected Behavior:** Allowing a hostname via `--allow-hosts` should permit all connections to that hostname, regardless of when DNS resolution occurs. **Actual Behavior:** Connections to IP addresses resolved at runtime are blocked, even if their corresponding hostnames are specified in `--allow-hosts`. **Additional Context:** This issue arises because `pytest-socket` resolves allowed hostnames to IP addresses only once at the beginning of the test session. If a library performs DNS resolution during test execution and obtains different IP addresses, these are not recognized as allowed, leading to blocked connections. A potential solution could involve resolving hostnames at the time of each connection attempt