REPRO STEPS:

1. npx playwright install
2. npx playwright test --shard=1/2
3. Move reports/blobs/report-1.zip to a temporary directory, so it isn't deleted by the next test run.
4. npx playwright test --shard=2/2
5. Move report-1.zip back into the reports/blobs directory.
6. npx playwright merge-reports --config merge.config.ts ./reports/blobs
7. Observe the time under testsuites in the merged junit report reports/merged/report.xml

Expected Result: time="3.729" The approximate total test time (with some floating point error)

Actual Result: time="0.025825..." Reported time is much lower than expected. Possibly the time the reports took to merge.