Add bcachefs fs tracking

[clonejo]

Further info on bcachefs: https://bcachefs.org/

• bcachefs has entered the stable kernel in 6.7.
• Some further mkfs/non-mount options, that could conceivably be tracked: number and type of disks in bcachefs and per target type, usage of options like --replicas, --erasure_code, --encrypted, compression.
• Since bcachefs does checksumming, recovered/non-recovered errors could also be tracked.

[clonejo]

hmm actually, i am not 100% sure what adding bcachefs to these lists actually does. The host file shows filesystem:bcachefs even without the patch.