[bugfix] Fix the application of the build flags

The '%{set_build_flags}' is unnecessary.
These flags are automatically called on the beginning of '%build' phase,
and are also part fo the '%cmake' macro.

The second call of CMake has to be run in "-N" mode,
which treats the CMake cache as read-only.

Related: RHEL-140363

galera.spec

@@ -43,8 +43,6 @@ u garb - 'Galera Arbitrator Daemon' /dev/null -
 EOF
 
 %build
-%{set_build_flags}
-
 
 %cmake \
        -DCMAKE_BUILD_TYPE="%{?with_debug:Debug}%{!?with_debug:RelWithDebInfo}" \
@@ -61,7 +59,7 @@ EOF
        -DINSTALL_LIBDIR="%{_lib}/galera" \
        -DINSTALL_MANPAGE="share/man/man8"
 
-cmake -B %_vpath_builddir -LAH
+cmake -B %_vpath_builddir -N -LAH
 
 %cmake_build