GraphBLAS: Avoid warning from Clang 17.

Clang 17 emits more warnings (or errors) when it comes to incompatible
pointer types.

`_InterlockedCompareExchange` is declared with `long volatile *` as the
type of its first input argument
See: https://learn.microsoft.com/en-us/cpp/intrinsics/interlockedcompareexchange-intrinsic-functions?view=msvc-170

`int32_t` is `int` on Windows. While `long` and `int` have the same size
on Windows (LLP64 data model), they are technically distinct types.

Avoid the compiler warning by casting to the pointer type expected by
that function.

GraphBLAS/Source/omp/include/GB_atomics.h

@@ -410,7 +410,7 @@
     #define GB_ATOMIC_COMPARE_EXCHANGE_32(target, expected, desired)        \
     (                                                                       \
         GB_PUN (int32_t, expected) ==                                       \
-            _InterlockedCompareExchange ((int32_t volatile *) (target),     \
+            _InterlockedCompareExchange ((long volatile *) (target),        \
             GB_PUN (int32_t, desired), GB_PUN (int32_t, expected))          \
     )