Background

When managing dynamic resources (e.g., network connections, client instances) with syncx.Pool, there's currently no built-in way to proactively destroy all resources in the pool when it's no longer needed.
The existing maxAge mechanism only passively cleans up expired resources, which isn't sufficient for scenarios like:

1. Removing an obsolete pool (e.g., when a target service goes offline)
2. Forcefully refreshing all resources in the pool (e.g., after configuration changes)
3. Avoiding resource leaks when pools are dynamically replaced in a map

Proposal

Add a destroyAll() method to syncx.Pool

Use Case Example

In industrial communication scenarios (e.g., Modbus client pools), when a device's address changes, we need to immediately clean up the old pool's connections. A destroyAll() method would make this safe and straightforward.