test: make fiber_stack.test tap-compatible

NO_DOC=internal
NO_CHANGELOG=internal

(cherry picked from commit 98f62cd0)

test/unit/fiber_stack.c

 #include "memory.h"
 #include "fiber.h"
-#include "unit.h"
 #include "trivia/util.h"
 #include "errinj.h"
 
+#define UNIT_TAP_COMPATIBLE 1
+#include "unit.h"
+
 static struct fiber_attr default_attr;
 
 /** Total count of allocated fibers in the cord. Including dead ones. */

test/unit/fiber_stack.result

-SystemError: fiber mprotect failed: Cannot allocate memory
-	*** main_f ***
-1..11
-ok 1 - fiber_attr: the default stack size is 528384, but 528384 is set via CMake
-ok 2 - mprotect: failed to setup fiber guard page
-ok 3 - mprotect: diag is armed after error
-ok 4 - allocated new
-ok 5 - madvise: non critical error on madvise hint
-ok 6 - madvise: diag is armed after error
-ok 7 - fiber is deleted
-ok 8 - fiber with custom stack
-ok 9 - allocated new
-ok 10 - expected leak detected
-ok 11 - fiber is deleted
-	*** main_f: done ***