run jobs in build stage only for master branch

as suggested in the template doc, these are cmake .. style builds in a way that end user or distro maintainer would use

clang_tidy, gcc_coverage, clang_sanitise already compile all code in different ways, this way we avoid 5 builds

in order to still detect very rare bugs that only happen in release mode (due to compiler optimising or CMakeLists error) still run them for master branch so they are stopped prior to releasing on a tag