chore(gpu): fix condition to trigger unsigned gpu test

.github/workflows/gpu_unsigned_integer_tests.yml

@@ -13,6 +13,7 @@ env:
   SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK }}
   FAST_TESTS: TRUE
   NIGHTLY_TESTS: FALSE
+  IS_PULL_REQUEST: ${{ github.event_name == 'pull_request' }}
   CHECKOUT_TOKEN: ${{ secrets.REPO_CHECKOUT_TOKEN || secrets.GITHUB_TOKEN }}
   # Secrets will be available only to zama-ai organization members
   SECRETS_AVAILABLE: ${{ secrets.JOB_SECRET != '' }}
@@ -22,7 +23,6 @@ on:
   # Allows you to run this workflow manually from the Actions tab as an alternative.
   workflow_dispatch:
   pull_request:
-    types: [ labeled ]
   schedule:
     # Nightly tests @ 1AM after each work day
     - cron: "0 1 * * MON-FRI"
@@ -66,11 +66,11 @@ jobs:
 
   setup-instance:
     name: Setup instance (cuda-unsigned-integer-tests)
+    runs-on: ubuntu-latest
     needs: should-run
     if: (github.event_name == 'schedule' && github.repository == 'zama-ai/tfhe-rs') ||
       github.event_name == 'workflow_dispatch' ||
       needs.should-run.outputs.gpu_test == 'true'
-    runs-on: ubuntu-latest
     outputs:
       runner-name: ${{ steps.start-remote-instance.outputs.label || steps.start-github-instance.outputs.runner_group }}
     steps: