Update CHANGELOG for JGit 7.3.0 upgrade

Co-authored-by: bartkamphorst <571173+bartkamphorst@users.noreply.github.com>

Author: Copilot

CHANGELOG

@@ -1,3 +1,7 @@
+# v.7.3.0.0
+* Upgrade JGit from v. 7.0.0.202409031743-r to 7.3.0.202506031305-r
+* Upgrade JGit SSH from v. 6.8.0.202311291450-r to 7.3.0.202506031305-r
+
 # v.0.3.0
 * Upgrade JGit (from v. 3.0.0 to 3.1.0)
 * Implemented Plumbing module for manipulating bare repositories