Issue #22181: The availability of the getrandom() is now checked in configure,
and stored in pyconfig.h as the new HAVE_GETRANDOM_SYSCALL define.

Fix os.urandom() tests using file descriptors if os.urandom() uses getrandom().
diff --git a/pyconfig.h.in b/pyconfig.h.in
index 10426c7..c8ce976 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -395,6 +395,9 @@
 /* Define to 1 if you have the `getpwent' function. */
 #undef HAVE_GETPWENT
 
+/* Define to 1 if the Linux getrandom() syscall is available */
+#undef HAVE_GETRANDOM_SYSCALL
+
 /* Define to 1 if you have the `getresgid' function. */
 #undef HAVE_GETRESGID