[DOCS] Update copyright year to 2026

Author: fsuter

Documentation/guides.xml

@@ -13,7 +13,7 @@
     <project
             title="External Import"
             release="8.1.3"
-            copyright="2007-2025"
+            copyright="2007-2026"
     />
     <inventory id="svconnector" url="https://docs.typo3.org/p/cobweb/svconnector/main/en-us/"/>
     <inventory id="tut" url="https://docs.typo3.org/p/cobweb/externalimport_tut/main/en-us/"/>