Fix: [AEA-0000] - set temporary instance for pull request (#2312)

## Summary

- Routine Change

### Details

- set proxygen instance as temporary for pull requests

Author: anthony-nhs

.github/scripts/deploy_api.sh

@@ -66,6 +66,8 @@ if [[ "${IS_PULL_REQUEST}" == "true" ]]; then
     jq --arg title "[PR-${pr_id}] $title" '.info.title = $title' "${SPEC_PATH}" > temp.json && mv temp.json "${SPEC_PATH}"
     echo "disabling monitoring for pull request deployment"
     jq '."x-nhsd-apim".monitoring = false' "${SPEC_PATH}" > temp.json && mv temp.json "${SPEC_PATH}"
+    echo "setting temporary true for pull request deployment"
+    jq '."x-nhsd-apim".temporary = true' "${SPEC_PATH}" > temp.json && mv temp.json "${SPEC_PATH}"
 fi
 
 # Find and replace the specification version number