RFR: 8378378: Remove references to obsolete jdk.net.usePlainDatagramSocketImpl property from tests

[Daniel Fuchs]

On Mon, 23 Feb 2026 01:14:28 GMT, Jaikiran Pai <jpai at openjdk.org> wrote:

> Can I please get a review of this test-only change which removes reference to the obsolete `jdk.net.usePlainDatagramSocketImpl` property?
> 
> This property and the related fallback support was removed in https://bugs.openjdk.org/browse/JDK-8253119. The property plays no role anymore. The tests continue to pass after this change.

LGTM

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Marked as reviewed by dfuchs (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/29871#pullrequestreview-3840296411