ci: re-trigger PR checks after benchmark baseline reset

The C++ Windows benchmark was failing against a stale baseline
cached from March 30. The baseline cache was deleted and a fresh
dispatch run established new measurements. This empty commit
triggers a pull_request run so the PR checks pick up the new
baseline.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: kovtcharov