Upgrade to OpenAPI 3.1.0 with prefixItems and streamlined validation

- Upgraded OpenAPI spec from 3.0.3 to 3.1.0
- Replaced QueueItem oneOf pattern with prefixItems for precise tuple validation
- Simplified GitHub Actions workflow to use only Python tests (removed redundant swagger-editor validation)
- All validation now handled by openapi-spec-validator which supports OpenAPI 3.1
- QueueItem now enforces exact tuple structure: [position, prompt_id, prompt, extra_data, outputs_to_execute]

.github/workflows/openapi-validation.yml

@@ -5,36 +5,20 @@ on:
     branches: [ master ]
     paths:
       - 'openapi.yaml'
+      - 'tests-api/openapi.yaml'
   pull_request:
     branches: [ master ]
     paths:
       - 'openapi.yaml'
+      - 'tests-api/openapi.yaml'
 
 jobs:
-  openapi-check:
+  validate:
     runs-on: ubuntu-latest
-
-    # Service containers to run with `runner-job`
-    services:
-      # Label used to access the service container
-      swagger-editor:
-        # Docker Hub image
-        image: swaggerapi/swagger-editor
-        ports:
-          # Maps port 8080 on service container to the host 80
-          - 80:8080
-
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Validate OpenAPI definition
-        uses: swaggerexpert/swagger-editor-validate@v1
-        with:
-          definition-file: openapi.yaml
-          swagger-editor-url: http://localhost/
-          default-timeout: 20000
-
       - name: Set up Python
         uses: actions/setup-python@v4
         with: