feat: remove assistants workspace definition (#108)

.changeset/plenty-pugs-hug.md

@@ -0,0 +1,7 @@
+---
+'@sketch-hq/sketch-file-format': patch
+---
+
+Do not define Assistants workspace item here in the file format. Assistants
+workspace is now only defined in the
+[Assistant Types](https://github.com/sketch-hq/sketch-assistants/tree/main/packages/types).

schema/workspace.schema.yaml

@@ -3,16 +3,8 @@ description:
   The workspace is a folder in the Sketch file archive that can contain
   arbitrary JSON files, allowing Sketch and 3rd party products and tools to
   store settings that should travel with the Sketch document. To avoid clashes
-  or settings being overridden, select a unique name for your workspace file. A
-  workspace file named `assistants` has been reserved for Sketch Assistant
-  settings, and is specified below. Note that custom layer-level data should
-  continue to be stored in `userInfo` of these objects, not within the
-  workspace.
+  or settings being overridden, select a unique name for your workspace file.
 type: object
 additionalProperties:
   type: object
   additionalProperties: true
-optional:
-  - assistants
-properties:
-  assistants: { $ref: ./objects/assistants-workspace.schema.yaml }