cannelloni: remove -DCMAKE_BUILD_TYPE=Release

this is the default

pkgs/os-specific/linux/cannelloni/default.nix

···
   buildInputs = lib.optionals sctpSupport [ lksctp-tools ];
 
   cmakeFlags = [
-    "-DCMAKE_BUILD_TYPE=Release"
     "-DSCTP_SUPPORT=${lib.boolToString sctpSupport}"
   ];