chore: teach set module about iter.Seq (#6676)

- Add a new `Seq` function to the `Set` type, this returns an iterator over the values.
- Convert some users of the `Values` method to allow for more optimal code.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/6676
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Co-authored-by: Gusted <postmaster@gusted.xyz>
Co-committed-by: Gusted <postmaster@gusted.xyz>

modules/container/set.go

@@ -3,6 +3,11 @@
 
 package container
 
+import (
+	"iter"
+	"maps"
+)
+
 type Set[T comparable] map[T]struct{}
 
 // SetOf creates a set and adds the specified elements to it.
@@ -63,3 +68,9 @@ func (s Set[T]) Values() []T {
 	}
 	return keys
 }
+
+// Seq returns a iterator over the elements in the set.
+// It returns a single-use iterator.
+func (s Set[T]) Seq() iter.Seq[T] {
+	return maps.Keys(s)
+}