doc/go1.18: remove some TODOs for changes we aren't mentioning
doc/go1.18: remove some TODOs for changes we aren't mentioning

Updates #47694

Change-Id: I8fdbded4aaf974425ee317a1cdd940a5ac88c0b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/368794
Trust: Jeremy Faller <b3f594e10a9edcf5413cf1190121d45078c62290@golang.org>
Run-TryBot: Jeremy Faller <b3f594e10a9edcf5413cf1190121d45078c62290@golang.org>
TryBot-Result: Gopher Robot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

cloudflare/go,CAFxX/go,golang/go,nawawi/go,nawawi/go,cloudflare/go,nawawi/go,nawawi/go,golang/go,golang/go,cloudflare/go,golang/go,CAFxX/go,CAFxX/go,cloudflare/go,nawawi/go,CAFxX/go,golang/go,cloudflare/go,cloudflare/go,nawawi/go,golang/go,nawawi/go,golang/go,cloudflare/go,CAFxX/go,CAFxX/go,CAFxX/go,nawawi/go,cloudflare/go,CAFxX/go,golang/go