fix: use valid ip mask in api keys when remote address is ipv6 (#2695)

coderd/users.go

@@ -815,6 +815,7 @@ func (api *API) createAPIKey(rw http.ResponseWriter, r *http.Request, params dat
 	if ip == nil {
 		ip = net.IPv4(0, 0, 0, 0)
 	}
+	bitlen := len(ip) * 8
 	key, err := api.Database.InsertAPIKey(r.Context(), database.InsertAPIKeyParams{
 		ID:              keyID,
 		UserID:          params.UserID,
@@ -822,7 +823,7 @@ func (api *API) createAPIKey(rw http.ResponseWriter, r *http.Request, params dat
 		IPAddress: pqtype.Inet{
 			IPNet: net.IPNet{
 				IP:   ip,
-				Mask: ip.DefaultMask(),
+				Mask: net.CIDRMask(bitlen, bitlen),
 			},
 			Valid: true,
 		},