Revert "feat: acts new parameter sortBy (#1637)"

This reverts commit f7c6887.

Author: janbuchar

apify-api/openapi/paths/actors/acts.yaml

@@ -15,9 +15,6 @@ get:
     order, therefore you can use pagination to incrementally fetch all Actors while new
     ones are still being created. To sort the records in descending order, use the `desc=1` parameter.
 
-    You can also sort by `lastRunStartedAt` by using the `sortBy=lastRunStartedAt` query parameter.
-    In this case, descending order means the most recently run Actor appears first.
-
   operationId: acts_get
   parameters:
     - name: my
@@ -61,15 +58,6 @@ get:
       schema:
         type: boolean
         example: true
-    - name: sortBy
-      in: query
-      description: |
-        Field to sort the records by. The default is `createdAt`. You can also use `lastRunStartedAt` to sort
-        by the most recently ran Actors.
-      schema:
-        type: string
-        enum: [createdAt, lastRunStartedAt]
-        example: createdAt
   responses:
     '200':
       description: ''