Matrix testing fix

[w-k-jones]

Fixes a bug in transform_feature_points which was causing the failing matrix tests. I also fixed a couple of other depreciation warnings in the tests, and added python 3.12 to matrix testing. Resolves #444

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Linting results by Pylint:

Your code has been rated at 8.72/10 (previous run: 8.72/10, +0.00) _{The linting score is an indicator that reflects how well your code version follows Pylint’s coding standards and quality metrics with respect to the RC_v1.5.x branch. A decrease usually indicates your new code does not fully meet style guidelines or has potential errors.}

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Codecov Report

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

Project coverage is 60.96%. Comparing base (4fa1efa) to head (81a580b). Report is 5 commits behind head on RC_v1.5.x.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## RC_v1.5.x #451 +/- ## ============================================= - Coverage 60.98% 60.96% -0.03% ============================================= Files 23 23 Lines 3550 3548 -2 ============================================= - Hits 2165 2163 -2 Misses 1385 1385 ``` | [Flag](https://app.codecov.io/gh/tobac-project/tobac/pull/451/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=tobac-project) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/tobac-project/tobac/pull/451/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=tobac-project) | `60.96% <100.00%> (-0.03%)` | :arrow_down: | 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=tobac-project#carryforward-flags-in-the-pull-request-comment) to find out more.

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[w-k-jones]

@JuliaKukulies @freemansw1 This should fix the matrix testing issues, are you happy to review?

[JuliaKukulies]

@w-k-jones, fyi I have merged in these changes in #450 and this fixes the matrix testing issue just as here