reef: mgr/diskprediction_local: avoid more mypy errors

reef: mgr/diskprediction_local: avoid more mypy errors

Similar to c4111033172db28c4737e8438f27901811919ce4 this patch
suppresses mypy errors in the diskprediction_local mgr module.
I probably put the magic comment on more lines than needed but
mypy does not have a block-comment method to suppress checking
for just a region of code today.
This patch is not a backport as the issue is only impacting
reef CI jobs and so it is applied directly to the reef branch.

Signed-off-by: John Mulligan <phlogistonjohn@asynchrono.us>