RFR: [java.io] Use @requires tag instead of exiting based on "os.name" property value

[Lance Andersen]

On Thu, 24 Apr 2025 20:46:42 GMT, Brian Burkhalter <bpb at openjdk.org> wrote:

> Use the `@requires` tag instead of obtaining the operating system name from the `os.name` property and then exiting if the test is not run on that operating system.

Marked as reviewed by lancea (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/24860#pullrequestreview-2792485973