Relax the bounds on HashSet: Debug

[CAD97]

This looks to be just an oversight.

The bounds on HashMap are similarly loose:

hashbrown/src/map.rs

Lines 1540 to 1545 in 1e1bb23

	impl<K, V, S, A> Debug for HashMap<K, V, S, A>
	where
	K: Debug,
	V: Debug,
	A: Allocator + Clone,
	{

And std::collections::HashSet has always only bounded T by Debug and not Eq/Hash here.

[Amanieu]

@bors r+

[bors]

📌 Commit 69e3da9 has been approved by Amanieu

[bors]

⌛ Testing commit 69e3da9 with merge 612057b...

[bors]

☀️ Test successful - checks-actions
Approved by: Amanieu
Pushing 612057b to master...