Vaadin Portlet to support Jakarta EE 10

[mshabarov]

The Jakarta Portlet project migrates the JSR 362 Specification and API from Java EE to Jakarta EE.

This is a good opportunity for Vaadin to support Vaadin Portlet add-on in Vaadin 24+ versions and let them work with Liferay.

Here are some links to follow:
https://liferay.dev/blogs/-/blogs/liferay-s-java-roadmap-for-2025
https://liferay.dev/blogs/-/blogs/preparing-for-jakarta
https://projects.eclipse.org/proposals/jakarta-portlet
https://liferay.atlassian.net/browse/LPD-49394

Summary:
Liferay Jakarta EE 10 migration timeline - Q3 2025,
Java 17 is deprecated, Java 21 - full focus.