ci: drop heavyweight ETW from repeated measurements

.github/workflows/bazel.yml

@@ -177,41 +177,21 @@ jobs:
           BAZEL_TEST_SHARD: ${{ matrix.shard }}
           BAZEL_TEST_SHARD_COUNT: 4
           BUILDBUDDY_API_KEY: ${{ secrets.BUILDBUDDY_API_KEY }}
-          WINDOWS_BAZEL_ETL_PATH: ${{ runner.temp }}/windows-bazel-trace-shard-${{ matrix.shard }}.etl
           WINDOWS_BAZEL_TELEMETRY_PATH: ${{ runner.temp }}/windows-bazel-telemetry-shard-${{ matrix.shard }}.csv
           WINDOWS_BAZEL_TELEMETRY_STOP_FILE: ${{ runner.temp }}/windows-bazel-telemetry-stop-shard-${{ matrix.shard }}
         shell: bash
         run: |
           set -euo pipefail
 
-          rm -f "${WINDOWS_BAZEL_ETL_PATH}" "${WINDOWS_BAZEL_TELEMETRY_PATH}" "${WINDOWS_BAZEL_TELEMETRY_STOP_FILE}"
+          rm -f "${WINDOWS_BAZEL_TELEMETRY_PATH}" "${WINDOWS_BAZEL_TELEMETRY_STOP_FILE}"
           pwsh -NoProfile -File .github/scripts/measure-windows-bazel.ps1 \
             -Mode monitor \
             -OutputPath "${WINDOWS_BAZEL_TELEMETRY_PATH}" \
             -StopFile "${WINDOWS_BAZEL_TELEMETRY_STOP_FILE}" &
           telemetry_pid=$!
-          etw_started=0
-          # Keep the trace broad enough to distinguish CPU, filesystem, disk,
-          # and network waits, but use light profiles to limit observer cost.
-          if wpr.exe \
-            -start CPU.light \
-            -start DiskIO.light \
-            -start FileIO.light \
-            -start Network.light \
-            -filemode; then
-            etw_started=1
-          else
-            echo "WPR resource profiles could not start; continuing with counter telemetry only." >&2
-          fi
           stop_telemetry() {
             touch "${WINDOWS_BAZEL_TELEMETRY_STOP_FILE}"
             wait "${telemetry_pid}" || true
-            if [[ "${etw_started}" -eq 1 ]]; then
-              if ! wpr.exe -stop "${WINDOWS_BAZEL_ETL_PATH}" -skipPdbGen -compress; then
-                echo "WPR resource trace could not be saved; cancelling its session." >&2
-                wpr.exe -cancel || true
-              fi
-            fi
           }
           trap stop_telemetry EXIT
 
@@ -280,7 +260,6 @@ jobs:
           path: |
             ${{ runner.temp }}/windows-bazel-telemetry-shard-${{ matrix.shard }}.csv
             ${{ runner.temp }}/windows-bazel-profile-shard-${{ matrix.shard }}.gz
-            ${{ runner.temp }}/windows-bazel-trace-shard-${{ matrix.shard }}.etl
           if-no-files-found: warn
 
       - name: Upload Bazel execution logs