LAGraph_Version: Use char array instead of pointer as argument

Enforce use of array with right size, prevent memory errors.
Found by GCC 16 (-Warray-paramter).

Author: gruenich

include/LAGraph.h

@@ -859,7 +859,7 @@ LAGRAPH_PUBLIC extern GrB_Semiring
  *
  * @param[out] version_number   an array of size 3; with the major, minor,
  *      and update versions of LAGraph, in that order.
- * @param[out] version_date     an array of size >= LAGraph_MSG_LEN, returned
+ * @param[out] version_date     an array of size LAGraph_MSG_LEN, returned
  *      with the date of this version of LAGraph.
  * @param[in,out] msg   any error messages.
  *
@@ -872,7 +872,7 @@ int LAGraph_Version
 (
     // output:
     int version_number [3], // user-provided array of size 3
-    char *version_date,     // user-provided array of size >= LAGRAPH_MSG_LEN
+    char version_date[LAGRAPH_MSG_LEN], // user-provided array of size LAGRAPH_MSG_LEN
     char *msg
 ) ;