GH-157724: Comment typo fixes ONLY for gc.c and gc_free_threading.c (no code changes)

- gc.c
  - At https://github.com/python/cpython/blob/f8bbe696f152d302e7eb3eeb0587a1933cae59fc/Python/gc.c#L3
    fix "infromation" to "information"
  - At https://github.com/python/cpython/blob/f8bbe696f152d302e7eb3eeb0587a1933cae59fc/Python/gc.c#L773
    fix "suble" to "subtle"
- gc_free_threading.c
  - At https://github.com/python/cpython/blob/f8bbe696f152d302e7eb3eeb0587a1933cae59fc/Python/gc_free_threading.c#L527
    fix "intructions" to "instructions"

Author: willy-b

Python/gc.c

@@ -1,6 +1,6 @@
 //  This implements the reference cycle garbage collector.
 //  The Python module interface to the collector is in gcmodule.c.
-//  See InternalDocs/garbage_collector.md for more infromation.
+//  See InternalDocs/garbage_collector.md for more information.
 
 #include "Python.h"
 #include "pycore_ceval.h"         // _Py_set_eval_breaker_bit()
@@ -770,7 +770,7 @@ move_legacy_finalizer_reachable(PyGC_Head *finalizers)
  * whose callbacks must be invoked.  See gc_weakref.txt for overview & some
  * details.
  *
- * The clearing of weakrefs is suble and must be done carefully, as there was
+ * The clearing of weakrefs is subtle and must be done carefully, as there were
  * previous bugs related to this.  First, weakrefs to the unreachable set of
  * objects must be cleared before we start calling `tp_clear`.  If we don't,
  * those weakrefs can reveal unreachable objects to Python-level code and that

Python/gc_free_threading.c

@@ -524,7 +524,7 @@ static_assert(BUFFER_HI < BUFFER_SIZE &&
               BUFFER_LO > 0,
               "Invalid prefetch buffer level settings.");
 
-// Prefetch intructions will fetch the line of data from memory that
+// Prefetch instructions will fetch the line of data from memory that
 // contains the byte specified with the source operand to a location in
 // the cache hierarchy specified by a locality hint.  The instruction
 // is only a hint and the CPU is free to ignore it.  Instructions and