Fix TREC-COVID regressions (take 2)

[lintool]

Follow up to #2196 - for whatever reason - most likely carelessness on my part - there are more effectiveness differences that I didn't capture - on the doc2query runs.

Running from scratch again to confirm:

# https://github.com/castorini/anserini/blob/master/docs/experiments-covid.md

python src/main/python/trec-covid/download_indexes.py --date 2020-07-16 &
python src/main/python/trec-covid/download_indexes.py --date 2020-06-19 &
python src/main/python/trec-covid/download_indexes.py --date 2020-05-19 &
python src/main/python/trec-covid/download_indexes.py --date 2020-05-01 &
python src/main/python/trec-covid/download_indexes.py --date 2020-04-10 &

nohup python src/main/python/trec-covid/generate_round5_baselines.py >& logs/log.trec-covid.round5 &
nohup python src/main/python/trec-covid/generate_round4_baselines.py >& logs/log.trec-covid.round4 &
nohup python src/main/python/trec-covid/generate_round3_baselines.py >& logs/log.trec-covid.round3 &
nohup python src/main/python/trec-covid/generate_round2_baselines.py >& logs/log.trec-covid.round2 &
nohup python src/main/python/trec-covid/generate_round1_baselines.py >& logs/log.trec-covid.round1 &

# https://github.com/castorini/anserini/blob/master/docs/experiments-covid-doc2query.md

python src/main/python/trec-covid/download_doc2query_indexes.py --date 2020-07-16 &
python src/main/python/trec-covid/download_doc2query_indexes.py --date 2020-06-19 &

nohup python src/main/python/trec-covid/generate_round5_doc2query_baselines.py >& logs/log.trec-covid.round5-docTTTTTquery &
nohup python src/main/python/trec-covid/generate_round4_doc2query_baselines.py >& logs/log.trec-covid.round4-docTTTTTquery &

[ronakice]

LGTM!

[lintool]

Update: I don't think it was because I was careless... I seem to be getting some level of non-determinism in the effectiveness figures. Investigating and will report-back further.

[lintool]

False alarm. Failed regressions caused by incomplete index downloads. I've confirmed that regressions run successfully on my iMac Pro (Intel), Mac Studio (M1), tuna, and linux.cs. Going ahead to merge now.