Fix enum types in JSON schemas (#1634)

`type: enum` does not exist, as an enum can be of any type.

Signed-off-by: Kévin Commaille <zecakeh@tedomum.fr>

data/api/server-server/definitions/event-schemas/m.device_list_update.yaml

@@ -31,7 +31,7 @@ allOf:
   - type: object
     properties:
       edu_type:
-        type: enum
+        type: string
         enum: ['m.device_list_update']
         description: The string `m.device_list_update`.
         example: "m.device_list_update"

data/api/server-server/definitions/event-schemas/m.direct_to_device.yaml

@@ -23,7 +23,7 @@ allOf:
   - type: object
     properties:
       edu_type:
-        type: enum
+        type: string
         enum: ['m.direct_to_device']
         description: The string `m.direct_to_device`.
         example: "m.direct_to_device"

data/api/server-server/definitions/event-schemas/m.presence.yaml

@@ -21,7 +21,7 @@ allOf:
   - type: object
     properties:
       edu_type:
-        type: enum
+        type: string
         enum: ['m.presence']
         description: The string `m.presence`
         example: "m.presence"
@@ -44,7 +44,7 @@ allOf:
                   description: The user ID this presence EDU is for.
                   example: "@john:matrix.org"
                 presence:
-                  type: enum
+                  type: string
                   enum: ['offline', 'unavailable', 'online']
                   description: The presence of the user.
                   example: "online"

data/api/server-server/definitions/event-schemas/m.receipt.yaml

@@ -24,7 +24,7 @@ allOf:
   - type: object
     properties:
       edu_type:
-        type: enum
+        type: string
         enum: ['m.receipt']
         description: The string `m.receipt`
         example: "m.receipt"

data/api/server-server/definitions/event-schemas/m.signing_key_update.yaml

@@ -23,7 +23,7 @@ allOf:
   - type: object
     properties:
       edu_type:
-        type: enum
+        type: string
         enum: ['m.signing_key_update']
         description: The string `m.signing_update`.
         example: "m.signing_key_update"

data/api/server-server/definitions/event-schemas/m.typing.yaml

@@ -20,7 +20,7 @@ allOf:
   - type: object
     properties:
       edu_type:
-        type: enum
+        type: string
         enum: ['m.typing']
         description: The string `m.typing`
         example: "m.typing"