openjdk-17-jre has
Depends: libgtk2.0-0t64 | libgtk-3-0t64

And includes this patch:
https://salsa.debian.org/openjdk-team/openjdk/-/blob/openjdk-17/debian/patches/keep-gtk2-as-default.patch

Debian Testing only has 2 gtk2 apps left: pidgin and the Debian
Installer. Meanwhile most Debian desktop systems will have gtk3
installed for Firefox ESR, etc. Please remove the alternate gtk2
dependency and the gtk2 patch.

Thank you,
Jeremy Bícha