TODO(sll) in .gcloudignore: Find a more structured way of ignoring files.

[FaithAbiola]

The TODO comment in the .gcloudignore file needs to be addressed.

Create a more structured way of excluding third-party files in the .gcloudignore file, rather than the current manual approach.

The .gcloudignore file is used to exclude certain files and directories from the Google Cloud deployments. The current approach of manually listing out all the third-party files and directories to exclude is not scalable and makes the file difficult to maintain. A more structured approach is needed.