Fix: Providers no longer burn files randomly

[TheMarstonConnell]

Since the dawn of Jackal, providers have randomly burned files. Here is the end to that.

[TheMarstonConnell]

These are some metrics showing this off. Burned files stays at zero even after more than 500 files are on the system.

[codecov[bot]]

Codecov Report

Attention: 86 lines in your changes are missing coverage. Please review.

Comparison is base (0bd35f1) 44.13% compared to head (6b1aa68) 43.87%.

Files	Patch %	Lines
x/storage/types/file_deal.go	0.00%	27 Missing :warning:
x/storage/types/file.go	0.00%	23 Missing :warning:
x/storage/keeper/rewards.go	40.90%	11 Missing and 2 partials :warning:
x/storage/types/params.go	7.14%	13 Missing :warning:
x/storage/keeper/msg_server_postproof.go	68.75%	4 Missing and 1 partial :warning:
x/storage/types/message_postproof.go	0.00%	2 Missing :warning:
x/storage/types/proof_loader.go	0.00%	2 Missing :warning:
x/storage/keeper/migrations.go	0.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #384 +/- ## ========================================== - Coverage 44.13% 43.87% -0.27% ========================================== Files 229 230 +1 Lines 8571 8643 +72 ========================================== + Hits 3783 3792 +9 - Misses 4555 4617 +62 - Partials 233 234 +1 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.