test(p/uint256): Increase Test Coverage for `uint256` Package #8512

Job	Run time
Run Main (autocounterd) / Go Build / generated	9s
Run Main (autocounterd) / Go Linter / lint	30s
Run Main (autocounterd) / Go Test / test	32s
Run Main (docker-integration) / Go Build / generated	5s
Run Main (docker-integration) / Go Linter / lint	9s
Run Main (docker-integration) / Go Test / test	16s
Run Main (genproto) / Go Build / generated	9s
Run Main (genproto) / Go Linter / lint	36s
Run Main (genproto) / Go Test / test	59s
Run Main (genstd) / Go Build / generated	9s
Run Main (genstd) / Go Linter / lint	18s
Run Main (genstd) / Go Test / test	23s
Run Main (goscan) / Go Linter / lint	12s
Run Main (goscan) / Go Build / generated	5s
Run Main (goscan) / Go Test / test	18s
Run Main (loop) / Go Build / generated	13s
Run Main (loop) / Go Linter / lint	38s
Run Main (loop) / Go Test / test	46s
	6m 27s

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