Add bison minimum version of 2.4.1 due to %code

Summary:
Some Mac OS versions have bison 2.3 even though it is very old.
%code is first handled in bison version 2.4; gnu site has 2.4.1 as
the earliest 2.4.x version.

Test Plan:
Verified build fails in cmake phase when using bison 2.3 and builds
correctly using bison 2.4.1+.

Reviewers: Frameworks, winterz

Reviewed By: winterz

Subscribers: pino, ltoscano, winterz, kde-frameworks-devel

Tags: Frameworks

Differential Revision: https://phabricator.kde.org/D19092