Reapply "Fix unused snapshots not triggering failure in CI"

[epenet]

This reverts commit 35b7c30.

Breaking change

Re-apply, with optimisations

We do not need to serialize/de-serialize the report unless --snapshot-update or --snapshot-details is set

Needs:

• Remove unused snapshots from Habitica #129499

Proposed change

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

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[jbouwh]

Looks good,
Tested mqtt CI tests with coverage in (46.32s), so all seems well.
Thanks @epenet 👍

[epenet]

Looks good, Tested mqtt CI tests with coverage in (46.32s), so all seems well. Thanks @epenet 👍

@frenck the regression for regular tests has been addressed.
Are we OK to merge this one back in?

[MartinHjelmare]

This isn't critical for the release, right?