Build: use the setting instead hardcoding it
@@ -563,7 +563,7 @@ class UpdateDocsTask(SyncRepositoryMixin, Task):
environment=self.get_vcs_env_vars(),
# Force the ``container_image`` to use one that has the latest
# ca-certificate package which is compatible with Lets Encrypt
- container_image='readthedocs/build:ubuntu-20.04',
+ container_image=settings.RTD_DOCKER_BUILD_SETTINGS['os']['ubuntu-20.04']
)
# Environment used for code checkout & initial configuration reading
