Update module golang.org/x/net to v0.28.0

This MR contains the following updates:

Package	Type	Update	Change
golang.org/x/net	require	minor	v0.26.0 -> v0.28.0

---

Configuration

Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

Automerge: Disabled by config. Please merge this manually once you are satisfied.

Rebasing: Whenever MR becomes conflicted, or you tick the rebase/retry checkbox.

Ignore: Close this MR and you won't be reminded about this update again.

---

• If you want to rebase/retry this MR, check this box

---

This MR has been generated by Renovate Bot.

go.mod

@@ -2,4 +2,4 @@ module git.autistici.org/ai3/tools/webdav-server-go
 
 go 1.19
 
-require golang.org/x/net v0.26.0
+require golang.org/x/net v0.28.0