[skip email] Remove checks for old data format

[alexpiet]

Pull Request instructions:

• Please follow the update protocol
• Answer the questions below in detail. Your responses will be emailed to experimenters.
• If the experimenters must do anything new, provide detailed step by step instructions on the wiki
• If computer maintainers need to manually update anything, provide detailed step by step instructions
• Use markdown syntax in order for your comments to be rendered reliably in the email: "1." instead of "1)", use four spaces for indents.
• If you use the keyword "skip email" in the title, it will skip the email updates
• Merges from "develop" into "production_testing" should use the keyword "production merge" in the title for reliable indexing of updates
• Merges from "production_testing" into "main" should use the keyword "update main"

Describe changes:

• Removes checks for TrainingFolder data organization, because its been long enough that all mice will have behavior folder organization
• Code is stable if a mouse has an old format session, it just wont get loaded

What issues or discussions does this update address?

• resolves #300

Describe the expected change in behavior from the perspective of the experimenter

• none

Describe any manual update steps for task computers

• none

Was this update tested in 446/447?

• [ ] tested in 447

[alexpiet]

@hanhou @XX-Yin This is ready for review