Setup nix flake #89

Job	Run time
Test non-Linux (macos-latest, stable)	20s
Lint	14s
Test non-Linux (macos-latest, stable, --features const-generics)	19s
Test Linux (stable, x86_64)	7s
Test non-Linux (windows-latest, stable)	23s
Test Linux (stable, i686)	59s
Test non-Linux (windows-latest, stable, --features const-generics)	22s
Test Linux (stable, sparc64)	1m 13s
Test Linux (stable, --features const-generics, x86_64)	7s
Test Linux (stable, --features const-generics, i686)	58s
Test Linux (stable, --features const-generics, sparc64)	1m 3s
Test Linux (beta, x86_64)	10s
Test Linux (beta, i686)	1m 7s
Test Linux (beta, sparc64)	1m 8s
Test Linux (beta, --features const-generics, x86_64)	11s
Test Linux (beta, --features const-generics, i686)	2m 52s
Test Linux (beta, --features const-generics, sparc64)	1m 8s
Test Linux (nightly, x86_64)	14s
Test Linux (nightly, i686)	3m 17s
Test Linux (nightly, sparc64)	1m 5s
Test Linux (nightly, --features const-generics, x86_64)	12s
Test Linux (nightly, --features const-generics, i686)	1m 8s
Test Linux (nightly, --features const-generics, sparc64)	1m 6s
Test Linux (1.37.0, x86_64)	18s
All Succeeded	2s
	20m 3s

Provide feedback