Use BuildConfig model in our code

[humitos]

This is the continuation work to finally make usage of the BuildConfig model instead of saving the readthedocs.yaml file inside Build._config itself.

The next step here is to delete the _config field once we are settled here and happy with this solution 👍🏼

References:

• Data migration for BuildConfig model #12698
• Builds: add data_hash field and update get_or_create method #12704
• Remove orphan BuildConfig models #12702
• Build: Add BuildConfig model for deduplicated config storage #12646

[ericholscher]

Would be good to have @stsewd review as well, but did a quick look.

[ericholscher]

@stsewd waiting on review from you to 👍 it

[stsewd]

We should change how the index is created #12704 before switching to this new modeling. Otherwise, it would be harder to change later.

[stsewd]

This was used because we needed to query other builds. You can change this to just values_list("readthedocs_yaml_config", flat=True)

[stsewd]

_readthedocs_yaml_config could have been assigned to None. In that case we won't have a build_config object.

[humitos]

We should change how the index is created #12704 before switching to this new modeling. Otherwise, it would be harder to change later.

I'm fine moving forward without that index for now. That was a test and it's not strictly required. I can do it later if it's required. It shouldn't be a lot of data. We have created 500k BuildConfig objects only from 24M Build. Also, we plan to delete old builds, so the number of BuildConfig will be reduced as well.

[stsewd]

I'd prefer if we deal with that now and not when the DB is overloaded in the future.