Harden FAL registration

[inlined]

1. Updates don't have to have every field (whatever happened to this being the default and using field_mask?)
2. A function trigger not being registered doesn't make the function undeletable

[gemini-code-assist]

Code Review

This pull request updates the AILogic service to handle 404 errors during trigger deletion by logging a warning instead of throwing an exception, and modifies the default value of allowMissing to true in updateTrigger. I recommend simplifying the error handling logic in ailogic.ts by utilizing the getErrStatus utility from src/error.ts to improve readability and maintain consistency with repository standards. Additionally, please verify if changing the default allowMissing parameter in updateTrigger could introduce unintended side effects for other callers.