Bump last release version to 6.8.0.202311291450-r

This is the version used to compare API changes against to detect
breaking API changes.

Change-Id: I005b6a24c98c507656ebab415492a4127f08d471

pom.xml

diff --git a/pom.xml b/pom.xml
index 6bce8e1..8bc3365 100644
--- a/pom.xml
+++ b/pom.xml
@@ -118,7 +118,7 @@
 
     <project.build.outputTimestamp>${commit.time.iso}</project.build.outputTimestamp>
 
-    <jgit-last-release-version>6.7.0.202309050840-r</jgit-last-release-version>
+    <jgit-last-release-version>6.8.0.202311291450-r</jgit-last-release-version>
     <ant-version>1.10.14</ant-version>
     <apache-sshd-version>2.11.0</apache-sshd-version>
     <jsch-version>0.1.55</jsch-version>