@philm The linked Arch Linux announcement contains incorrect information, pacman -Syu jdk-openjdk DOES NOT WORK.
What does work is pacman -Sy jdk-openjdk followed by pacman -Syu.
https://bbs.archlinux.org/viewtopic.php?pid=2129801#p2129801
$ sudo pacman -Syu jdk-openjdk
:: Synchronising package databases...
core is up to date
extra is up to date
multilib is up to date
:: Starting full system upgrade...
:: Replace kdsoap with extra/kdsoap-qt5? [Y/n]
:: Replace kuserfeedback with extra/kuserfeedback5? [Y/n]
:: Replace libqaccessibilityclient with extra/libqaccessibilityclient-qt5? [Y/n]
resolving dependencies...
looking for conflicting packages...
error: unresolvable package conflicts detected
error: failed to prepare transaction (conflicting dependencies)
:: jdk-openjdk and jre-openjdk are in conflict
$ sudo pacman -Sy jdk-openjdk
:: Synchronising package databases...
core is up to date
extra is up to date
multilib is up to date
resolving dependencies...
looking for conflicting packages...
:: jdk-openjdk and jre-openjdk are in conflict. Remove jre-openjdk? [y/N] y
:: jdk-openjdk and jre-openjdk-headless are in conflict. Remove jre-openjdk-headless? [y/N] y
Packages (3) jre-openjdk-21.u35-3 [removal] jre-openjdk-headless-21.u35-3 [removal]
jdk-openjdk-21.u35-8
Total Download Size: 457.46 MiB
Total Installed Size: 1136.47 MiB
Net Upgrade Size: 634.32 MiB
:: Proceed with installation? [Y/n] Y