fix: Export `RemoveDeadFuncsError` #3329

Job	Run time
Check for changes in Python files	3s
Build HUGR binary	43s
check python 3.10	14s
check python 3.13	14s
Check serialization schema	7s
test python 3.10	38s
test python 3.13	40s
Required checks 🐍	1s
	2m 40s

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