[native] preserve Symbol-keyed styles without processing

[vincentriemer]

[native] preserve Symbol-keyed styles without processing

This diff makes is so that if the native StyleX polyfill encounters a style key that is a Symbol it always passes its value through losslessly to the result.

[github-actions]

workflow: benchmarks/size

Comparison of minified (terser) and compressed (brotli) size results, measured in bytes. Smaller is better.

Results	Base	Patch	Ratio
react-strict-dom/dist/web/index.js
· compressed	3,251	3,251	1.00
· minified	10,375	10,375	1.00
react-strict-dom/dist/web/runtime.js
· compressed	1,645	1,645	1.00
· minified	4,131	4,131	1.00
react-strict-dom/dist/native/index.js
· compressed	16,555	16,670	1.01	+
· minified	64,094	64,712	1.01	+
react-strict-animated/dist/web/index.js
· compressed	6,861	6,861	1.00
· minified	23,486	23,486	1.00
react-strict-animated/dist/native/index.js
· compressed	797	797	1.00
· minified	2,518	2,518	1.00

[github-actions]

workflow: benchmarks/perf (native)

Comparison of performance test results, measured in operations per second. Larger is better.

Results	Base	Patch	Ratio
css.create
· small	1,144,195	854,118	0.75	!!
· small with units	488,098	421,119	0.86	!!
· small with variables	670,630	565,877	0.84	!!
· several small	349,138	289,183	0.83	!!
· large	198,856	178,847	0.90	!!
· large with polyfills	148,588	135,734	0.91	!!
· complex	102,469	90,819	0.89	!!
· unsupported	209,220	191,264	0.91	!!
css.createTheme
· simple theme	227,537	228,263	1.00	+
· polyfill theme	215,157	212,083	0.99	-