doc/next: minor grammar fix in release notes

For #66626.
For #68545.

Change-Id: I4fe21bdaa9580eb087c849de72e98f6145121dd0
Reviewed-on: https://go-review.googlesource.com/c/go/+/633282
Reviewed-by: Robert Griesemer <[email protected]>
Auto-Submit: Robert Griesemer <[email protected]>
Reviewed-by: Alan Donovan <[email protected]>
TryBot-Bypass: Robert Griesemer <[email protected]>

doc/next/6-stdlib/99-minor/go/types/66626.md

@@ -1,6 +1,6 @@
 
 All `go/types` data structures that expose sequences using a pair of
-methods such as `Len() int` and `At(int) T` now also methods that
+methods such as `Len() int` and `At(int) T` now also have methods that
 return iterators, allowing you to simplify code such as this:
 
 ```go