Pump minimum Bison version to 3.0

It's available in Debian oldstable, so 'everywhere'.

See: https://invent.kde.org/frameworks/solid/-/merge_requests/44

CMakeLists.txt

@@ -65,7 +65,7 @@ set_package_properties(FLEX PROPERTIES
     PURPOSE "Required for the Trader parser"
 )
 
-find_package(BISON 2.4.1 REQUIRED)
+find_package(BISON 3.0 REQUIRED)
 set_package_properties(BISON PROPERTIES
     URL "http://www.gnu.org/software/bison"
     DESCRIPTION "general-purpose parser generator"