CAMEL-23214: Migrate AvailablePortFinder in camel-vertx tests

[gnodet]

Migrate AvailablePortFinder.getNextAvailable() to the @RegisterExtension pattern using AvailablePortFinder.Port in camel-vertx, camel-vertx-http, and camel-vertx-websocket test classes.

This is part of the effort to split #22101 into per-component PRs.

[github-actions]

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