Fix broken pip install command

Author: marbre

.github/workflows/ci-sglang-benchmark.yml

@@ -69,7 +69,7 @@ jobs:
           pip install --no-compile -r requirements.txt -e sharktank/ shortfin/
 
           # Pin to known-working versions.
-          pip install -f https://iree.dev/pip-release-links.html
+          pip install -f https://iree.dev/pip-release-links.html \
             iree-base-compiler==3.1.0rc20241220 \
             iree-base-runtime==3.1.0rc20241220 \
             "numpy<2.0"