fix: store status offences only when slashing enabled

[0xArdi]

Fixes

This PR makes it s.t. offence status changes are only stored in the DB if slashing is enabled.

Types of changes

What types of changes does your code introduce? (A breaking change is a fix or feature that would cause existing functionality and APIs to not work as expected.) Put an x in the box that applies

• [x] Non-breaking fix (non-breaking change which fixes an issue)
• [ ] Breaking fix (breaking change which fixes an issue)
• [ ] Non-breaking feature (non-breaking change which adds functionality)
• [ ] Breaking feature (breaking change which adds functionality)
• [ ] Refactor (non-breaking change which changes implementation)
• [ ] Messy (mixture of the above - requires explanation!)

Checklist

Put an x in the boxes that apply.

• [x] I have read the CONTRIBUTING doc
• [x] I am making a pull request against the main branch (left side). Also you should start your branch off our main.
• [x] Lint and unit tests pass locally with my changes
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] I have locally run services that could be impacted and they do not present failures derived from my changes
• [x] Public-facing documentation has been updated with the changes affected by this PR. Even if the provided contents are not in their final form, all significant information must be included.
• [x] Any backwards-incompatible/breaking change has been clearly documented in the upgrading document.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 94.40%. Comparing base (112e5db) to head (8bdce08).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #2222 +/- ## ======================================= Coverage 94.39% 94.40% ======================================= Files 260 260 Lines 16104 16110 +6 ======================================= + Hits 15202 15208 +6 Misses 902 902 ``` | [Flag](https://app.codecov.io/gh/valory-xyz/open-autonomy/pull/2222/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=valory-xyz) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/valory-xyz/open-autonomy/pull/2222/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=valory-xyz) | `94.40% <100.00%> (+<0.01%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=valory-xyz#carryforward-flags-in-the-pull-request-comment) to find out more.

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