fix: remove stray duplicate from serving benchmark config (#46870)

Signed-off-by: cmiyai <cmiyai@bu.edu>
Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>
Co-authored-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

.pre-commit-config.yaml

@@ -154,6 +154,11 @@ repos:
         --python-version, "3.12",
       ]
       files: ^requirements/docs\.(in|txt)$
+- repo: https://github.com/pre-commit/pre-commit-hooks
+  rev: 3e8a8703264a2f4a69428a0aa4dcb512790b2c8c
+  hooks:
+  - id: check-json
+    files: ^\.buildkite/.*\.json$
 - repo: local
   hooks:
   - id: format-torch-nightly-test