Make `MinimalFuture` cancelation atomic. This prevents HTTP request cancelation logic from racily completing the future with an error.
--------- - [x] I confirm that I make this contribution in accordance with the [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). ------------- Commit messages: - 8380967: Canceled HttpClient.sendAsync futures throw inconsistent exceptions Changes: https://git.openjdk.org/jdk/pull/31758/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=31758&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8380967 Stats: 15 lines in 2 files changed: 3 ins; 6 del; 6 mod Patch: https://git.openjdk.org/jdk/pull/31758.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/31758/head:pull/31758 PR: https://git.openjdk.org/jdk/pull/31758
