feat(py)!: Rename package to `hugr` #86

Job	Run time
Check for changes in Rust files	4s
benches	1m 34s
tests (Rust 1.75)	1m 31s
check	47s
tests (Rust beta)	1m 58s
tests (Rust nightly)	1m 18s
tests (Rust stable)	1m 11s
Required checks 🦀	1s
coverage	1m 53s
	10m 17s

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