Make `Directory` its own distribution kind #6166

Job	Run time
Determine changes	5s
cargo fmt	26s
build binary \| linux	1m 51s
cargo clippy \| ubuntu	48s
cargo clippy \| windows	2m 55s
cargo test \| ubuntu	4m 3s
cargo test \| macos	4m 11s
cargo test \| windows	6m 13s
check windows trampoline	3m 24s
build binary \| macos aarch64	1m 11s
build binary \| macos x86_64	2m 15s
build binary \| windows	2m 18s
benchmarks	2m 14s
check system \| python on fedora	31s
check cache \| ubuntu	47s
check system \| python on debian	45s
ecosystem test \| prefecthq/prefect	1m 48s
check system \| python on opensuse	38s
ecosystem test \| pallets/flask	14s
check system \| pypy on ubuntu	32s
check system \| python on rocky linux 8	30s
check system \| python on rocky linux 9	38s
check system \| alpine	20s
check system \| amazonlinux	30s
check system \| python on ubuntu	24s
check system \| python via pyenv	1m 41s
check system \| pyston	3m 47s
check system \| python3.12 via chocolatey	54s
check system \| python3.13 on windows	1m 12s
check system \| python3.10 on windows	40s
check system \| python3.10 on windows x86	45s
check system \| embedded python3.10 on windows	24s
check cache \| macos aarch64	12s
check system \| conda3.8 on linux	44s
check system \| homebrew python on macos aarch64	18s
check system \| conda3.11 on linux	42s
check system \| python on macos aarch64	14s
check system \| conda3.8 on windows	2m 18s
check system \| conda3.11 on windows	2m 17s
check system \| conda3.8 on macos	42s
check system \| conda3.11 on macos	43s
check system \| python on macos x86_64	24s
	57m 28s

Provide feedback