iscc: Fix running windows installers

Fix found by AleXoundOS

> I figured out what caused the problem! By default, mkDerivation uses strip operations for all binaries in $out/bin,
> what caused $out/bin/Setup.e32 file to become stripped and lose some crucial parts which must be copied to resulting installer executable.
> Adding dontStrip = 1 fixes the problem.

Co-authored-by: Alexander Tomokhov <[e-mail]>

pkgs/by-name/is/iscc/package.nix

···
     runHook postInstall
   '';
 
+  # Stripping causes `$out/bin/Setup.e32` to lose something important and causes the built windows installers to not run on windows "This app can't run on your PC".
+  # They worked in wine but not on real windows.
+  dontStrip = 1;
+
   meta = with lib; {
     description = "Compiler for Inno Setup, a tool for creating Windows installers";
     homepage = "https://jrsoftware.org/isinfo.php";