This reverts commit 6638dc5526.
Setting RelWithDebInfo can cause issues since cmake macros often handle
only Release or Debug build but not RelWithDebInf which might cause
issues https://github.com/void-linux/void-packages/pull/10948
It is advised to set -DCMAKE_BUILD_TYPE=RelWithDebInfo manually in
packages that ignore our CFLAGS or patch them to use them
closes#10948