Update API CONTRIBUTING.md

Description

This is out of date:

If there's agreement on a given change and this is your first pull request for Jakarta Bean Validation,
please sign the [Contributor License Agreement](https://cla.jboss.org/) for the "Jakarta Bean Validation" project.

We need a new blurb pointing to the Eclipse process.

Environment

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Status

Assignee

Unassigned

Reporter

Guillaume Smet

Labels

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Worked in

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Feedback Requested

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Feedback Requested By

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backPortable

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Community Help Wanted

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Suitable for new contributors

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Requires Release Note

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Pull Request

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backportDecision

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backportReEvaluate

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Priority

Major
Configure