fixes #22883; replace `default(typeof(` with `reset`; suppress `Unsaf… (#22895)

fixes #22883

…eDefault` warnings

avoid issues mentioned by https://forum.nim-lang.org namely, it
allocated unnecessary stack objects in the loop

```c
while (1)
{
tyObject_N__8DSNqSGSHBKOhI8CqSgAow T5_;
nimZeroMem((void *)(&T5_), sizeof(tyObject_N__8DSNqSGSHBKOhI8CqSgAow));
eqsink___test4954_u450((&(*t_p0).data.p->data[i].Field1), T5_);
}
```

It might be more efficient in some cases

follow up https://github.com/nim-lang/Nim/pull/21821

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/pure/collections/sets.nim b/lib/pure/collections/sets.nim
index 220ef3bb6..99bb299d5 100644
--- a/lib/pure/collections/sets.nim
+++ b/lib/pure/collections/sets.nim
@@ -382,7 +382,7 @@ proc clear*[A](s: var HashSet[A]) =
   s.counter = 0
   for i in 0 ..< s.data.len:
     s.data[i].hcode = 0
-    s.data[i].key = default(typeof(s.data[i].key))
+    reset(s.data[i].key)
 
 
 proc union*[A](s1, s2: HashSet[A]): HashSet[A] =
@@ -816,7 +816,7 @@ proc clear*[A](s: var OrderedSet[A]) =
   for i in 0 ..< s.data.len:
     s.data[i].hcode = 0
     s.data[i].next = 0
-    s.data[i].key = default(typeof(s.data[i].key))
+    reset(s.data[i].key)
 
 proc len*[A](s: OrderedSet[A]): int {.inline.} =
   ## Returns the number of elements in `s`.