nixpkgs: drop support for 24.05 (#751) #1286

Job	Run time
examples-darwin	3m 7s
check-fmt	37s
check-dead-code	21s
examples-linux (alt-registry)	1m 18s
examples-linux (build-std)	1m 18s
tests (https://nixos.org/nix/install)	1m 57s
examples-linux (cross-musl)	1m 18s
tests (https://releases.nixos.org/nix/nix-2.24.10/install, --override-input nixpkgs $(./ci/ref-fr...	2m 16s
examples-linux (cross-rust-overlay)	1m 24s
examples-linux (cross-windows)	1m 21s
examples-linux (custom-toolchain)	1m 17s
examples-linux (end-to-end-testing)	1m 22s
examples-linux (quick-start)	1m 18s
examples-linux (quick-start-simple)	1m 16s
examples-linux (quick-start-workspace)	1m 20s
examples-linux (sqlx)	1m 18s
examples-linux (trunk-workspace)	1m 20s
examples-linux (trunk)	1m 17s
all systems go	0s
	25m 25s

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