Fix `ProverKey::serialization_size`

[moCello]

Resolves #743

[codecov[bot]]

Codecov Report

Merging #744 (dbe5d04) into master (0ec5bb9) will increase coverage by 0.01%. The diff coverage is 83.33%.

:exclamation: Current head dbe5d04 differs from pull request most recent head 62775f5. Consider uploading reports for the commit 62775f5 to get more accurate results

Additional details and impacted files

[](https://codecov.io/gh/dusk-network/plonk/pull/744?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dusk-network) ```diff @@ Coverage Diff @@ ## master #744 +/- ## ========================================== + Coverage 84.72% 84.74% +0.01% ========================================== Files 53 53 Lines 4092 4097 +5 ========================================== + Hits 3467 3472 +5 Misses 625 625 ``` | [Impacted Files](https://codecov.io/gh/dusk-network/plonk/pull/744?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dusk-network) | Coverage Δ | | |---|---|---| | [src/constraint\_system/constraint.rs](https://codecov.io/gh/dusk-network/plonk/pull/744?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dusk-network#diff-c3JjL2NvbnN0cmFpbnRfc3lzdGVtL2NvbnN0cmFpbnQucnM=) | `60.25% <0.00%> (ø)` | | | [src/proof\_system/widget.rs](https://codecov.io/gh/dusk-network/plonk/pull/744?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dusk-network#diff-c3JjL3Byb29mX3N5c3RlbS93aWRnZXQucnM=) | `88.95% <ø> (ø)` | | | [tests/append\_gate.rs](https://codecov.io/gh/dusk-network/plonk/pull/744?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dusk-network#diff-dGVzdHMvYXBwZW5kX2dhdGUucnM=) | `89.04% <100.00%> (+0.80%)` | :arrow_up: | ------ [Continue to review full report at Codecov](https://codecov.io/gh/dusk-network/plonk/pull/744?src=pr&el=continue&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dusk-network). > **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dusk-network) > `Δ = absolute (impact)`, `ø = not affected`, `? = missing data` > Powered by [Codecov](https://codecov.io/gh/dusk-network/plonk/pull/744?src=pr&el=footer&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dusk-network). Last update [0ec5bb9...62775f5](https://codecov.io/gh/dusk-network/plonk/pull/744?src=pr&el=lastupdated&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dusk-network). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dusk-network).