Ethereum Improvement Proposal 7983 (EIP-7983) enforces transaction gas limits during block validation, automatically rejecting any transaction that exceeds the cap

Quotes that support claims

Transactions that specify a gas limit exceeding 16.77 million would be rejected during block validation, making them ineligible for inclusion in new blocks.

Similarly, during block validation, any block that contains a transaction that exceeds the set gas limit will become invalid.