bpo-35561: Supress valgrind false alarm on epoll_ctl(event) (GH-18060)

Update Misc/valgrind-python.supp to suppress the false alarm.
(cherry picked from commit d8ef64422a)

Co-authored-by: Zackery Spytz <zspytz@gmail.com>

Misc/valgrind-python.supp

@@ -263,6 +263,14 @@
 
 }
 
+{
+   Uninitialised byte(s) false alarm, see bpo-35561
+   Memcheck:Param
+   epoll_ctl(event)
+   fun:epoll_ctl
+   fun:pyepoll_internal_ctl
+}
+
 {
    ZLIB problems, see test_gzip
    Memcheck:Cond