fix!: delete deprecated attribute authorized_gae_applications

[kam1kaze]

Just delete the latest deprecated attribute related to First Generation instances. Fix #219

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[comment-bot-dev]

Thanks for the PR! 🚀
✅ Lint checks have passed.

[kam1kaze]

I don't have access to Cloud Build logs, so I've no idea why terraform-google-sql-db--int-trigger test failed.

[bharathkkb]

Thanks @kam1kaze it's due to #231 and not related to change