In the current code, an `IllegalStateException` might be thrown from the try block while invoking the `removeLockKeyInnerUnlink()` method, especially when caused by key expiration (resulting in `unlinkResult == false`).
This triggers the check block, which incorrectly sets the `unlinkAvailable` flag to `false`, even if the Redis server supports the unlink operation.
As a consequence, the subsequent `removeLockKeyInnerDelete()` method is invoked when it should not be.
* `IllegalStateException` should not be thrown from try block
* Add a comment and fix Checkstyle violations
**Cherry-pick to `6.1.x` & `6.0.x`**
(cherry picked from commit ba6d35d123)
d1f18b1d8c