`safe_dump` of a dict with a tuple key produces YAML that `safe_load` cannot parse

[BoxiYu]

import yaml
s = yaml.safe_dump({(1, 2): 0})   # succeeds -> '? - 1\n  - 2\n: 0\n'
yaml.safe_load(s)                 # ConstructorError: while constructing a mapping ...

Environment: PyYAML 6.0.3, Python 3.13.12.

safe_dump produces YAML with a complex (sequence) key that safe_load refuses to construct — a round-trip asymmetry. Found by round-trip testing (233/3000 random structured inputs).