[CT-1102] [Feature] .dbtignore

[jtcohen6]

Is this your first time submitting a feature request?

• I have read the expectations for open source contributors
• I have searched the existing issues, and I could not find an existing issue for this feature
• I am requesting a straightforward extension of existing dbt functionality, rather than a Big Idea better suited to a discussion

Describe the feature

A .dbtignore file that uses .gitignore syntax (including pattern matching) to define files that should NOT be parsed/loaded by dbt.

Code for this would go in read_files

After thinking about this for 5 minutes, I don't think there would be unintended consequences for partial parsing. If a file is ignored, it's as if it were deleted; if it's un-ignored, it's as if it were created for the first time.

Describe alternatives you've considered

Regex support for model-paths, test-paths, etc. Gross

Who will this benefit?

https://getdbt.slack.com/archives/C03QUA7DWCW/p1661873024869149

Concretely, people who have .py files in their dbt projects that are not actually Python models!

Are you interested in contributing this feature?

No response

Anything else?

Another use case where this has come up: Removing unneeded files in dbt packages (#4837). Unfortunately, because of how dbt installs Hub packages, this would still require downloading all files and then deleting the "ignored" ones. See conversation in dbt-labs/hubcap#95.

[lostmygithubaccount]

there is this: https://github.com/mherrmann/gitignore_parser I'm not sure we should be comfortable using directly but likely implement what we'd need

obviously we could go find the source C code in here: https://github.com/git/git

from a quick look it didn't seem like the more standard GitPython package natively supports exactly this, but also probably useful: https://github.com/gitpython-developers/GitPython

similar functionality for .amlignore here: https://github.com/Azure/azure-sdk-for-python/blob/3a9c7813f3a41f18dd9ca07b1994f9b7d2785359/sdk/ml/azure-ai-ml/azure/ai/ml/_utils/_asset_utils.py