Use Catch2 v3

[codecov-commenter]

Codecov Report

Attention: 5 lines in your changes are missing coverage. Please review.

Comparison is base (fe0b6f8) 90.53% compared to head (0f24d39) 90.53%.

Files	Patch %	Lines
test/flex_vector_transient/generic.ipp	50.00%	4 Missing :warning:
test/map/generic.ipp	92.85%	1 Missing :warning:

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Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #279 +/- ## ======================================= Coverage 90.53% 90.53% ======================================= Files 119 120 +1 Lines 12144 12147 +3 ======================================= + Hits 10994 10997 +3 Misses 1150 1150 ```

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