enable_checkpointing=False not possible

[blumenstiel]

Describe the issue
Setting enable_checkpointing: false is no possible because it leards to this error:

lightning.fabric.utilities.exceptions.MisconfigurationException: Trainer was configured with `enable_checkpointing=False` but found `ModelCheckpoint` in callbacks list.

This is because TerraTorch manually defines checkpoints.

Expected behavior (optional)
Handle checkpoints in a way that you can deacitvate it without manually overwriting ModelCheckpoint in the config.

[Joao-L-S-Almeida]

@blumenstiel Let me know if the solution purposed in the PR linked to this issue is the enough.

[blumenstiel]

@Joao-L-S-Almeida Thanks for looking into it. I reviewed the pr, still needs some changes.