ci: use double quotes #1350

Job	Run time
check-dead-code	22s
tests (https://nixos.org/nix/install)	2m 22s
check-fmt	42s
tests (https://releases.nixos.org/nix/nix-2.24.10/install, --override-input nixpkgs $(./ci/ref-fr...	2m 52s
examples-darwin	3m 45s
examples-linux (alt-registry)	1m 35s
examples-linux (build-std)	1m 40s
examples-linux (cross-musl)	1m 38s
examples-linux (cross-rust-overlay)	1m 33s
examples-linux (cross-windows)	1m 31s
examples-linux (custom-toolchain)	1m 35s
examples-linux (end-to-end-testing)	1m 32s
examples-linux (quick-start)	1m 29s
examples-linux (quick-start-simple)	1m 28s
examples-linux (quick-start-workspace)	1m 39s
examples-linux (sqlx)	1m 29s
examples-linux (trunk-workspace)	1m 33s
examples-linux (trunk)	1m 36s
all systems go	0s
	30m 21s

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