[PRQ#49055] Deletion Request for java-15-openjdk

MarsSeed [1] filed a deletion request for java-15-openjdk [2]: Cleanup of JDK 15 short-term support packages. JDK 15 is EOL since 2021-03-15; not even security patches get delivered after that date. Users should migrate to a newer JDK/JRE. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/java-15-openjdk/