Bump software version to 2.5

Update kSoftwareVersion in firmware-template-gd32/include/software_version.h from "2.4" to "2.5" to reflect the new release.

Author: vanvught

firmware-template-gd32/include/software_version.h

@@ -26,6 +26,6 @@
 #ifndef SOFTWARE_VERSION_H_
 #define SOFTWARE_VERSION_H_
 
-constexpr char kSoftwareVersion[] = "2.4";
+constexpr char kSoftwareVersion[] = "2.5";
 
 #endif // SOFTWARE_VERSION_H_