Re-add knock's `otherwise, reject` per MSC2403 (#3661)

* Re-add knock's `otherwise, reject` per MSC2403

Fixes https://github.com/matrix-org/matrix-doc/issues/3648

* changelog + changelog for 3432

changelogs/room_versions/newsfragments/3432.clarification

@@ -0,0 +1 @@
+Fully specify room versions to indicate what exactly is carried over from parent versions.

changelogs/room_versions/newsfragments/3661.clarification

@@ -0,0 +1 @@
+Fully specify room versions to indicate what exactly is carried over from parent versions.

content/rooms/fragments/v8-auth-rules.md

@@ -113,6 +113,7 @@ The rules are as follows:
         2.  If `sender` does not match `state_key`, reject.
         3.  If the `sender`'s current membership is not `ban`, `invite`,
             or `join`, allow.
+        4.  Otherwise, reject.
     8.  Otherwise, the membership is unknown. Reject.
 5.  If the `sender`'s current membership state is not `join`, reject.
 6.  If type is `m.room.third_party_invite`:

content/rooms/v7.md

@@ -136,6 +136,7 @@ The rules are as follows:
         2.  If `sender` does not match `state_key`, reject.
         3.  If the `sender`'s current membership is not `ban`, `invite`,
             or `join`, allow.
+        4.  Otherwise, reject.
     7.  Otherwise, the membership is unknown. Reject.
 5.  If the `sender`'s current membership state is not `join`, reject.
 6.  If type is `m.room.third_party_invite`: