ci: fix perf job invocation; guard optional imports in cli

Author: Karthikprasadm

.github/workflows/ci.yml

@@ -75,11 +75,11 @@ jobs:
       - name: Run benchmarks
         working-directory: sup-lang
         run: |
-          python -m sup.tools.benchmarks --case arith_loop --iters 5 --json --out ../perf.json
+          python sup/tools/benchmarks.py --case arith_loop --iters 5 --json --out ../perf.json
       - name: Enforce performance budgets
         working-directory: sup-lang
         run: |
-          python -m sup.tools.bench_gates
+          python sup/tools/bench_gates.py
       - name: Upload artifact
         uses: actions/upload-artifact@v4
         with: