Update tycho pomless extension to 2.6.0

Change-Id: Iaa958902c8622e0db2accfce53a61e74b137095b
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.releng.aggregator/+/189867
Tested-by: Alexander Kurtakov <akurtako@redhat.com>
Reviewed-by: Alexander Kurtakov <akurtako@redhat.com>
diff --git a/.mvn/extensions.xml b/.mvn/extensions.xml
index 45abef0..5d315bc 100644
--- a/.mvn/extensions.xml
+++ b/.mvn/extensions.xml
@@ -4,6 +4,6 @@
   <extension>
     <groupId>org.eclipse.tycho.extras</groupId>
     <artifactId>tycho-pomless</artifactId>
-    <version>2.5.0</version>
+    <version>2.6.0</version>
   </extension>
 </extensions>
\ No newline at end of file