Throttle Windows Bazel test concurrency (#18192)

## Summary
- cap the Windows Bazel test lane at `--jobs=8` to reduce local runner
pressure
- keep Linux and macOS Bazel test concurrency unchanged
- make failed-test log tailing resolve `bazel-testlogs` with the same CI
config and Windows host-platform context as the failed invocation
- prefer Bazel-reported `test.log` paths and normalize Windows path
separators before tailing

## Context
The Windows Bazel workflow currently uses `ci-windows`, which does not
inherit the remote executor config. This means the lane runs the `//...`
test suite locally and otherwise falls back to the repo-wide `common
--jobs=30`. The new Windows-only override is intended to reduce local
executor pressure without changing coverage.

## Validation
Not run locally; this is a CI workflow change and the draft PR is
intended to exercise the GitHub Actions lane directly.

---------

Co-authored-by: Codex <noreply@openai.com>

.github/workflows/bazel.yml

@@ -86,17 +86,21 @@ jobs:
             --print-failed-test-logs
             --use-node-test-env
           )
+          bazel_test_args=(
+            test
+            --test_tag_filters=-argument-comment-lint
+            --test_verbose_timeout_warnings
+            --build_metadata=COMMIT_SHA=${GITHUB_SHA}
+          )
           if [[ "${RUNNER_OS}" == "Windows" ]]; then
             bazel_wrapper_args+=(--windows-msvc-host-platform)
+            bazel_test_args+=(--jobs=8)
           fi
 
           ./.github/scripts/run-bazel-ci.sh \
             "${bazel_wrapper_args[@]}" \
             -- \
-            test \
-            --test_tag_filters=-argument-comment-lint \
-            --test_verbose_timeout_warnings \
-            --build_metadata=COMMIT_SHA=${GITHUB_SHA} \
+            "${bazel_test_args[@]}" \
             -- \
             "${bazel_targets[@]}"