coreutils: fix tests depending on setuid/setgid bits

(cherry picked from commit 6a850d2b11)

pkgs/tools/misc/coreutils/default.nix

@@ -31,6 +31,9 @@ stdenv.mkDerivation rec {
     sed '2i echo Skipping cp sparse test && exit 0' -i ./tests/cp/sparse.sh
     sed '2i echo Skipping rm deep-2 test && exit 0' -i ./tests/rm/deep-2.sh
     sed '2i echo Skipping du long-from-unreadable test && exit 0' -i ./tests/du/long-from-unreadable.sh
+    sed '2i echo Skipping chmod setgid test && exit 0' -i ./tests/chmod/setgid.sh
+    substituteInPlace ./tests/install/install-C.sh \
+      --replace 'mode3=2755' 'mode3=1755'
   '';
 
   outputs = [ "out" "info" ];