securefs: fix build w/glibc-2.34

Tests don't work in the sandbox and vendored catch2 doesn't compile, so
we disable the tests.

Failing Hydra build: https://hydra.nixos.org/build/163981825

pkgs/tools/filesystems/securefs/default.nix

@@ -20,6 +20,10 @@ stdenv.mkDerivation rec {
     ./add-macfuse-support.patch
   ];
 
+  postPatch = ''
+    sed -i -e '/TEST_SOURCES/d' CMakeLists.txt
+  '';
+
   nativeBuildInputs = [ cmake ];
   buildInputs = [ fuse ];