fix: pool-manager max spread assertion

[kerber0x]

Description and Motivation

Related Issues

This is an issue we solved in the past in V1, but somehow was lingering in V2.

---

Checklist:

• [x] I have read Migaloo's contribution guidelines.
• [x] My pull request has a sound title and description (not something vague like Update index.md)
• [x] All existing and new tests are passing.
• [x] I updated/added relevant documentation.
• [x] The code is formatted properly cargo fmt --all --.
• [x] Clippy doesn't report any issues cargo clippy -- -D warnings.
• [x] I have regenerated the schemas if needed cargo schema.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 80.64516% with 6 lines in your changes are missing coverage. Please review.

Project coverage is 89.91%. Comparing base (deebeee) to head (b75f791). Report is 2 commits behind head on release/v2_contracts.

:exclamation: Current head b75f791 differs from pull request most recent head 05d5afc. Consider uploading reports for the commit 05d5afc to get more accurate results

Files	Patch %	Lines
...ontracts/liquidity_hub/pool-manager/src/helpers.rs	50.00%	6 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## release/v2_contracts #348 +/- ## ======================================================== + Coverage 89.86% 89.91% +0.04% ======================================================== Files 261 261 Lines 27339 27334 -5 ======================================================== + Hits 24569 24576 +7 + Misses 2770 2758 -12 ```

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