Adds cft.json to .gitignore

[joaovitor]

The cft.json created in this codelab is being commited by mistake in some prs. This can generate leak and bad usage.

Adding cft.json go .gitignore can avoid versioning files that should not be versioned.

https://codelabs.developers.google.com/cft-onboarding?hl=en#3

[joaovitor]

https://github.com/terraform-google-modules/terraform-google-cloud-storage/pull/172

https://github.com/terraform-google-modules/terraform-google-cloud-storage/pull/71/

[joaovitor]

@kunalkg11 can you please review this PR?

[apeabody]

/gcbrun

[comment-bot-dev]

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

[github-actions[bot]]

This PR is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 7 days

[bharathkkb]

fixed by https://github.com/terraform-google-modules/terraform-google-cloud-storage/pull/199