RFR: 8355650: Remove unused fields in ParkEvent

[Coleen Phillimore]

On Sun, 27 Apr 2025 00:44:47 GMT, Zhengyu Gu <zgu at openjdk.org> wrote:

> Please review this trivial change that removes unused `TState` and `Notified` members in `ParkEvent`.

Looks good and trivial.

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Marked as reviewed by coleenp (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/24902#pullrequestreview-2806844195