Improve perf of Dict and Set #155

Job	Run time
check-changes	19s
ran-none	0s
start-nix-linux-x86-64-tests / nix-linux-x86	18m 43s
start-nix-linux-aarch64-cargo-build-test / nix-linux-arm64	44m 0s
start-nix-linux-aarch64-build-default-test / nix-linux-arm64	48m 40s
start-macos-x86-64-tests / test zig, rust, wasm...	8m 52s
start-nix-macos-apple-silicon-tests / nix-apple-silicon	16m 31s
start-roc-benchmarks / benchmark roc programs	5m 44s
start-ubuntu-x86-64-tests / test zig, rust, wasm...	7m 59s
start-windows-release-build-test / windows-release-build	14m 10s
start-windows-tests / windows-test-subset	24m 48s
ran-full	0s
finish	0s
	3h 9m 46s

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