Protect against crash in the `relation_possible` predicate with ambiguous relations. It was still possible to get a KeyError when using relations that are ambiguous at both ends, like (Executable, version_of, Program) & (Version, version_of, Project). Closes #3010148.

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sync_schema_props_perms('state_of')

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sync_schema_props_perms('transition_of')

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for etype in ('State', 'BaseTransition', 'Transition', 'WorkflowTransition'):

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    sync_schema_props_perms((etype, 'name', 'String'))

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