feat!: `used_extensions` calls for both ops and signatures #2824

Job	Run time
Check for changes in Python files	4s
Build HUGR binary	54s
Check serialization schema	13s
check python 3.10	17s
check python 3.13	21s
test python 3.10	28s
test python 3.13	33s
Required checks 🐍	1s
	2m 51s

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