Describe the bug

From the parquet specification.

If, in the last block, less than miniblocks are needed to store the values, the bytes storing the bit widths of the unneeded miniblocks are still present, their value should be zero, but readers must accept arbitrary values as well.

This is particularly important at the moment because of #1416 which causes the padding to be arbitrary in the event an encoder is reused.

To Reproduce

This is one of the underlying bugs behind apache/datafusion#1976

Expected behavior

The decoder should ignore the padded miniblock bit widths