Update README and compiler target to Java 17 in several plugins

[rzo1]

For all changes

• Is there a issue associated with this PR? Is it referenced in the commit message?

• Does your PR title start with #XXXX where XXXX is the issue number you are trying to resolve?

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For code changes

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• If applicable, have you updated the NOTICE file, including the main NOTICE file?

Note

Fixes the comments raised during last release.