chore: Fix benchmark summary credentials

In #7462 the aztec commenter github token was removed from the
bench-comment job in favor of loading secrets in the earthly-ci wrapper
script. However, the token was never injected into env, so the
bench-summary was silently failing due to invalid credentials.

.github/workflows/ci.yml

@@ -255,6 +255,8 @@ jobs:
         working-directory: ./yarn-project/scripts
         run: |
           earthly-ci -P +bench-comment
+        env:
+          AZTEC_BOT_GITHUB_TOKEN: ${{ secrets.AZTEC_BOT_GITHUB_TOKEN }}
 
   bb-gcc:
     needs: [build-images, changes]