contrib/packaging/spec: Use git-core instead of full git

See: https://discussion.fedoraproject.org/t/f42-change-proposal-switch-to-git-core-self-contained/138975

Author: travier

contrib/packaging/bootupd.spec

@@ -15,7 +15,7 @@ Source1:        %{url}/releases/download/v%{version}/bootupd-%{version}-vendor.t
 ExcludeArch:    %{ix86}
 %endif
 
-BuildRequires: git
+BuildRequires: git-core
 # For now, see upstream
 BuildRequires: make
 BuildRequires:  openssl-devel