SDK: Add stdlib.h include to pull in abort() (backport #21700) (#21704)

* SDK: Add stdlib.h include to pull in `abort()` (#21700)

(cherry picked from commit 923720f529)

# Conflicts:
#	sdk/bpf/c/inc/sol/assert.h

* Fix merge conflict

Co-authored-by: Jon Cinque <jon.cinque@gmail.com>

sdk/bpf/c/inc/solana_sdk.h

@@ -699,6 +699,7 @@ uint64_t entrypoint(const uint8_t *input);
  * Stub functions when building tests
  */
 #include <stdio.h>
+#include <stdlib.h>
 void sol_log_(const char *s, uint64_t len) {
   printf("Program log: %s\n", s);
 }