mir: improve set construction syntax #5141

Job	Run time
Provide additional context for the workflow	7s
Build release binaries (Linux)	6m 48s
Build release binaries (macOS)	6m 3s
Build release binaries (macOS (M1))	3m 7s
Build release binaries (Windows)	12m 21s
Build source archive	2m 36s
Build and test tooling (Linux)	2m 52s
Test the compiler and stdlib (Linux, batch #0)	6m 0s
Build and test tooling (macOS)	3m 34s
Build docs and release artifacts (Linux)	7m 5s
Test the compiler and stdlib (Linux, batch #1)	5m 40s
Build and test tooling (macOS (M1))	2m 27s
Build docs and release artifacts (macOS)	7m 32s
Test the compiler and stdlib (macOS, batch #0)	6m 57s
Build and test tooling (Windows)	3m 25s
Build docs and release artifacts (macOS (M1))	4m 58s
Test the compiler and stdlib (macOS, batch #1)	6m 51s
Build docs and release artifacts (Windows)	12m 37s
Test the compiler and stdlib (macOS (M1), batch #0)	3m 42s
Test the compiler and stdlib (macOS (M1), batch #1)	4m 8s
Test the compiler and stdlib (Windows, batch #0)	10m 19s
Test the compiler and stdlib (Windows, batch #1)	11m 3s
Build release artifacts from source archive (Linux)	9m 51s
Build release artifacts from source archive (macOS)	16m 43s
Build release artifacts from source archive (macOS (M1))	6m 0s
Build release artifacts from source archive (Windows)	18m 5s
Test release artifacts	28s
All check passed	1s
	3h 1m 20s

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