Patch smart contracts containing invalid annotations

Context

Solve issue #2450 (closed). Following !4366 (merged) some annotations have become invalid. Currently on mainnet there's one script containing such an annotation. This patch aims at correcting it to an acceptable format in the protocol migration. This will allow us to remove support for legacy annotation in the next protocol.

Manually testing the MR

1. Start mainnet a node.
2. Typecheck the code of smart contract KT1SL6CGhjPUyLypDbFv9bXsNF2sHG7Fy3j9. Make sure legacy mode is disabled. It should not typecheck.
3. Perform protocol migration to protocol alpha.
4. Typecheck the same contract again. Make sure legacy mode is disabled. The contract should typecheck.

Checklist

• Provide automatic testing (see the testing guide).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR