[data] Fixes #32 by reverting some of the changes from 05bbb35f

pyproject.toml

src/ptbench/data/montgomery/datamodule.py

src/ptbench/data/montgomery/default.py

src/ptbench/data/montgomery/fold_0.py

src/ptbench/data/montgomery/fold_1.py

src/ptbench/data/montgomery/fold_2.py

src/ptbench/data/montgomery/fold_3.py

src/ptbench/data/montgomery/fold_4.py

src/ptbench/data/montgomery/fold_5.py

src/ptbench/data/montgomery/fold_6.py

src/ptbench/data/montgomery/fold_7.py

src/ptbench/data/montgomery/fold_8.py

src/ptbench/data/montgomery/fold_9.py

src/ptbench/data/shenzhen/datamodule.py

src/ptbench/data/shenzhen/default.py

src/ptbench/data/shenzhen/fold_0.py

src/ptbench/data/shenzhen/fold_1.py

src/ptbench/data/shenzhen/fold_2.py

src/ptbench/data/shenzhen/fold_3.py

src/ptbench/data/shenzhen/fold_4.py