feat: add GitHub Copilot configuration #506

Job	Run time
Build Regorus FFI: (x86_64-pc-windows-msvc)	6m 57s
Build Regorus FFI: (x86_64-unknown-linux-gnu)	3m 58s
Build Regorus FFI: (aarch64-apple-darwin)	5m 27s
Build Regorus nuget	1m 0s
Test Regorus Nuget: (aarch64-apple-darwin)	50s
Test Regorus Nuget: (x86_64-unknown-linux-gnu)	57s
Test Regorus Nuget: (x86_64-pc-windows-msvc)	1m 59s
	21m 8s

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