Explicitly define write permission for PRs

.github/workflows/gha_workflow_llama_models_tests.yml

@@ -47,19 +47,21 @@ on:
 
       api_key:
         description: 'Provider API key'
-        required: true
+        required: false
         default: "---"
 
 env: 
   TOKENIZER_PATH: "models/llama3/api/tokenizer.model"  
   MODELS_PATH: "/data/llama3.2"
   VISION_MODEL_CHECKPOINT_DIR: "/data/llama3.2/${{ inputs.model_vision }}"
   TEXT_MODEL_CHECKPOINT_DIR: "/data/llama3.2/${{ inputs.model_text }}"
-  API_KEY: "${{ inputs.api_key }}"
+  API_KEY: "${{ inputs.api_key || '' }}"
 
 jobs:
   execute_workflow:
     name: Execute workload on Self-Hosted CPU k8s runner
+    permissions:
+      pull-requests: write
     defaults:
       run:
         shell: bash # default shell to run all steps for a given job.