Update geant4 version v11.3.0 and readme

Author: stewartboogert

README.md

@@ -1,7 +1,7 @@
 # Workflows for compiling Geant4 on mac
 
 ## Builds 
- * Geant4 (4.10.7, 4.11.0, 4.11.1, 4.11.2)
+ * Geant4 (4.10.7, 4.11.0, 4.11.1, 4.11.2, 4.11.3)
  * Apple and Intel silicon (macOS-13, macOS-14, macOS-15)
 
 ## Usage