[NFC] Apply linter/formatter fixes to data loader files

[vepadulano]

No description provided.

[guitargeek]

LGTM, it's good to make sure the linter checks are green!

I only have a concern about the Python code formatting, unrelated to this PR: the check in the CI doesn't seem to work correctly. @siliataider, maybe you can understand what's happening there? If I remember correctly, you introduced these checks.

[siliataider]

LGTM, it's good to make sure the linter checks are green!

I only have a concern about the Python code formatting, unrelated to this PR: the check in the CI doesn't seem to work correctly. @siliataider, maybe you can understand what's happening there? If I remember correctly, you introduced these checks.

Thanks @guitargeek for catching this! Indeed there was a recent change in the logic of computing the diff, this PR should take care of the issue # #21130