Upgrade to Infinispan 16.3.1

See:

• https://infinispan.org/blog/2026/10/07/infinispan-16-3
• https://github.com/infinispan/infinispan/releases#release-16.3.1 (from 16.2.3)

Infinispan 16.3 deprecated JavaSerializationMarshaller (which logs a warning at startup), so XWiki now uses the default Infinispan marshaller (ProtoStream) for its caches: the serialization element was removed from the default WEB-INF/cache/infinispan/config.xml. With the default configuration, the only cache which is serialized is the LESS skin files cache (file store), which only contains strings.

If you customized your WEB-INF/cache/infinispan/config.xml to persist (or distribute) caches containing other types of values, you can switch back to the previous marshaller by adding the following to the cache-container element (it is deprecated and will be removed in a future version of Infinispan):

<serialization marshaller="org.infinispan.commons.marshall.JavaSerializationMarshaller"/>