Socket timeout reading repository from ci.eclipse.org

After fixing the Jenkins build breakage due to the tycho-eclipserun-plugin to tycho-eclipse-plugin migration, I am getting repeated timeouts but on different files for e.g. https://ci.eclipse.org/qvt-oml/job/justj-promoter/144/

!ENTRY org.eclipse.equinox.p2.transformer 4 0 2025-10-05 08:18:06.894
!MESSAGE Messages while mirroring artifact descriptors.
!SUBENTRY 1 org.eclipse.equinox.p2.transport.ecf 4 1002 2025-10-05 08:18:06.895
!MESSAGE Unable to read repository at https://ci.eclipse.org/qvt-oml/job/qvto-master/712/artifact/releng/org.eclipse.qvto.releng.build-site/target/repository/plugins/org.eclipse.m2m.qvt.oml.tools.coverage.startup.source_1.11.0.v20251005-0803.jar.
!STACK 0
java.net.SocketTimeoutException: Read timed out
	at java.base/sun.nio.ch.NioSocketImpl.timedRead(NioSocketImpl.java:283)```

The relevant files have been accessible from Firefox for many minutes. It seems that the ci.eclipse.org interface is running slow again. #5125 (closed) never provided a solution.