Creating release notes for version 8.7.5

Author: alexanderrichards

ganga/GangaRelease/ReleaseNotes-8.7.5

@@ -0,0 +1,13 @@
+**************************************************************************************************************
+8.7.5 (2024/04/05)
+
+--------------------------------------------------------------------------------------------------------------
+ganga/ganga/GangaCore
+--------------------------------------------------------------------------------------------------------------
+* Update to python3 in some run scripts #2269 
+
+--------------------------------------------------------------------------------------------------------------
+ganga/ganga/GangaLHCb
+--------------------------------------------------------------------------------------------------------------
+* Fix GaudiExec Dirac RTHandler #2315 , #2316 
+* Fix Executable Dirac RTHandler for python3 #2312