Use jazzct for (S)CT checking

[J08nY]

The (S)CT checking in Jasmin is now done via the jazzct standalone checker (jasmin-lang/jasmin#766).
Thus, Makefile.checksct should use that (it is currently broken, AFAICT).

The blockers are:

• No support for -I include paths in the jazzct binary, only via JASMINPATH.
• For DOIT checking only (Let's DOIT: Add support for DOIT-instruction list in (S)CT checkers jasmin-lang/jasmin#736). No support for -lea, -lazy-regalloc or -noinsertarraycopy in jazzct, as these matter when checking is done after many compiler passes (and some primitives do not compile without them).