`Util/Util.cpp` always compiled (Follow-up from "Resolve "better solution to create/update src/OPALrevision.h")

The following discussion from !381 (merged) should be addressed:

• @kraus started a discussion: (+1 comment)

  The downside of the current method is that Util/Util.cpp is compiled every time make is called. It is compiled even if there are no other files that have to be compiled, e.g. when calling make twice without changing anything inbetween.

changed milestone to %OPAL 2.4.0

added Enhancement label

created merge request !391 (merged) to address this issue

mentioned in merge request !391 (merged)

closed via merge request !391 (merged)

mentioned in commit 68141137

marked the checklist item @kraus started a discussion: (+1 comment) as completed