Revert accidentally pushed commits

This reverts commits:
c11991f9de.
f8bf0fa0ac.
7abdd45c06.
92db4e20da.

data/api/client-server/notifications.yaml

@@ -126,7 +126,6 @@ paths:
                       description: The ID of the room in which the event was posted.
                     ts:
                       type: integer
-                      format: int64
                       description: |-
                         The unix timestamp at which the event notification was sent,
                         in milliseconds.

data/api/client-server/profile.yaml

@@ -56,7 +56,6 @@ paths:
               displayname:
                 type: string
                 description: The new display name for this user.
-            required: ["displayname"]
       responses:
         200:
           description: The display name was set.
@@ -132,7 +131,6 @@ paths:
                 type: string
                 format: uri
                 description: The new avatar URL for this user.
-            required: ["avatar_url"]
       responses:
         200:
           description: The avatar URL was set.

data/api/client-server/registration.yaml

@@ -352,10 +352,9 @@ paths:
                 example: "ihatebananas"
               logout_devices:
                 type: boolean
-                default: true
                 description: |-
                   Whether the user's other access tokens, and their associated devices, should be
-                  revoked if the request succeeds.
+                  revoked if the request succeeds. Defaults to true.
 
                   When `false`, the server can still take advantage of the [soft logout method](/client-server-api/#soft-logout)
                   for the user's remaining devices.

openapi_extensions.md

@@ -54,8 +54,6 @@ doesn't work, as in the following example:
           properties:
             ...
 ```
-This can only be used to define the type of named properties. In particular,
-the current tooling does not support `oneOf` inside `additionalProperties`.
 
 ## OpenAPI 3's "2xx" format for response codes