Build: fix API call to version.patch()

[stsewd]

The attribute in the serializer isn't declared as allow_null=True, so the call to patch fails for projects that aren't using this new build_data feature.

readthedocs.org/readthedocs/projects/tasks/builds.py

Lines 597 to 606 in 385398e

	api_v2.version(self.data.version.pk).patch(
	{
	"built": True,
	"documentation_type": self.data.version.documentation_type,
	"has_pdf": "pdf" in valid_artifacts,
	"has_epub": "epub" in valid_artifacts,
	"has_htmlzip": "htmlzip" in valid_artifacts,
	"build_data": self.data.version.build_data,
	}
	)

We could also add allow_null=True in the attribute, I'm fine with that solution too.

This also fixes tests on .com.

[humitos]

We could also add allow_null=True in the attribute, I'm fine with that solution too.

Yes, this is the correct way 👍🏼

[humitos]

Just wanted to note here that this is not failing now in production because we rolled back the builders, since they were failing due to a PATH miss configuration.