GHSA-JF2R-X3J4-23M7 OpenVM allows the byte decomposition of pc in AUIPC chip to overflow

The fix to https://cantina.xyz/code/c486d600-bed0-4fc6-aed1-de759fd29fa2/findings/21 has a typo that still results in the highest limb of pc being range checked to 8-bits instead of 6-bits. In the AIR, we do...