[tz] [PROPOSED] difftime isn’t pure either

[Paul Eggert]

See <https://sourceware.org/bugzilla/show_bug.cgi?id=31808#c1>.
* private.h (difftime): No longer pure.
---
 private.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/private.h b/private.h
index cacbe444..0c91a252 100644
--- a/private.h
+++ b/private.h
@@ -702,7 +702,7 @@ DEPRECATED_IN_C23 char *ctime(time_t const *);
 char *asctime_r(struct tm const *restrict, char *restrict);
 char *ctime_r(time_t const *, char *);
 #endif
-ATTRIBUTE_PURE double difftime(time_t, time_t);
+double difftime(time_t, time_t);
 size_t strftime(char *restrict, size_t, char const *restrict,
 		struct tm const *restrict);
 # if HAVE_STRFTIME_L
-- 
2.45.1