Remove declared-invalid `invite->knock` restriction from auth rules (#1175)

* Remove declared-invalid `invite->knock` restriction from auth rules

* Changelog

* real changelog

changelogs/room_versions/newsfragments/1175.clarification

@@ -0,0 +1 @@
+For room versions 7 through 10: Clarify that `invite->knock` is actually a legal transition.

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

@@ -118,8 +118,7 @@ The rules are as follows:
     7. If `membership` is `knock`:
         1.  If the `join_rule` is anything other than `knock`, reject.
         2.  If `sender` does not match `state_key`, reject.
-        3.  If the `sender`'s current membership is not `ban`, `invite`,
-            or `join`, allow.
+        3.  If the `sender`'s current membership is not `ban` 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.

content/rooms/v10.md

@@ -193,8 +193,7 @@ The rules are as follows:
             If the `join_rule` is anything other than `knock` or
             `knock_restricted`, reject.
         2.  If `sender` does not match `state_key`, reject.
-        3.  If the `sender`'s current membership is not `ban`, `invite`,
-            or `join`, allow.
+        3.  If the `sender`'s current membership is not `ban` 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.

content/rooms/v7.md

@@ -135,8 +135,7 @@ The rules are as follows:
     6. If `membership` is `knock`:
         1.  If the `join_rule` is anything other than `knock`, reject.
         2.  If `sender` does not match `state_key`, reject.
-        3.  If the `sender`'s current membership is not `ban`, `invite`,
-            or `join`, allow.
+        3.  If the `sender`'s current membership is not `ban` 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.