fix: raise errors for invalid shears and PixelScale WCS inits

[beckermr]

This PR adds runtime init error checking to the Shear class. It uses the equinox.error_if function. The net result is that the code now raises for invalid shears. Unfortunately there is no way to raise exceptions besides the equinox.EquinoxRuntimeError and according to the equinox issue tracker, enabling custom exceptions is not a feature they plan to support. We can't use subclassing IIUIC because the inheritance goes the wrong way.

xref: #237

[codspeed-hq]

Merging this PR will improve performance by 33.46%

⚠️ Unknown Walltime execution environment detected

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⚡ 1 improved benchmark
✅ 35 untouched benchmarks

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	test_benchmarks_lanczos_interp[xval-no_conserve_dc-run]	1,105.5 µs	828.3 µs	+33.46%

Tip

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_{Comparing equinox-errs (85569db) with main (d69a8ba)}

[beckermr]

OK @ismael-mendoza! This is the first PR in a series that adds runtime init checks to the various classes. I don't think I'll request review for all of them, but I wanted to get eyes on the first one so we all understand the syntax and implications. Please take a look!