libs: use nfs4j-0.26.0

Motivation:

new Major version with highlights:

Minor Feature release. Highlights:

 - added subs for remote quota service
 - Java 17

Changelog for nfs4j-0.25.0..nfs4j-0.26.0
* [ad31e60] [maven-release-plugin] prepare for next development iteration
* [40ccd76] build(deps): bump ch.qos.logback:logback-classic from 1.2.3 to 1.2.13
* [d167a07] build(deps): bump org.springframework:spring-context
* [55a5ddc] build(deps): bump com.hazelcast:hazelcast from 5.3.0 to 5.3.5
* [0ce8d2a] vfs: make file handle immutable class
* [bd0798b] pom: use java17
* [02a7c55] proj: add basic server for quick testing
* [c4cb94d] rquota: add xdrs for rquota protocol
* [0597235] rquota: add stub for rquota service
* [c58a552] rquota: add possibility to set quota.
* [0923c1b] github: add github build action
* [d744fd4] github: add autopublishing of releases
* [b9b92db] docs: add nfs42_prot.x nfs_xattr.x rquota.x
* [37904c9] [maven-release-plugin] prepare branch @{releaseLabel}
* [1f171e6] [maven-release-plugin] prepare release nfs4j-0.26.0

Acked-by: Marina Sahakyan
Target: master
Require-book: no
Require-notes: yes

pom.xml

@@ -765,7 +765,7 @@
         <dependency>
             <groupId>org.dcache</groupId>
             <artifactId>nfs4j-core</artifactId>
-            <version>0.25.0</version>
+            <version>0.26.0</version>
         </dependency>
         <dependency>
             <groupId>com.github.nitram509</groupId>