unpin system-tests (back to @main) (#308)

Author: nccatoni

.github/workflows/dev.yml

@@ -197,15 +197,14 @@ jobs:
 
   system-tests:
     needs: build-system-tests-artifact
-    uses: DataDog/system-tests/.github/workflows/system-tests.yml@1e5d6b7096279ca43ce4826fda3cc805635b63c1
+    uses: DataDog/system-tests/.github/workflows/system-tests.yml@main
     secrets:
       TEST_OPTIMIZATION_API_KEY: ${{ secrets.DD_CI_VIS_API_KEY }}
     permissions:
       contents: read
       id-token: write
     with:
       library: cpp
-      ref: 1e5d6b7096279ca43ce4826fda3cc805635b63c1
       binaries_artifact: system_tests_binaries
       parametric_job_count: 8  # dedicated parameter to speed up parametric job
       scenarios: PARAMETRIC