Update other build configuration

The master branch of this repository has been migrated to main using the [master-to-main](https://github.com/guardian/master-to-main) tool.

Please check any build related configuration and update as required:

- [ ] TeamCity - See the required steps in the [migrating.md](https://github.com/guardian/master-to-main/blob/main/migrating.md#update-ci-typically-teamcity) document
- [ ] Change snyk github integration(s) - it uses the default branch, but you will need to delete and reimport the project+file as this is the only way to refresh the default branch at present.
- [ ] Any other externally configured analysis tooling your team is using e.g. travis CI

It's probably a good idea to merge test PR to main once this is complete, to make sure that everything is working as expected. :slightly_smiling_face:

Start with the TeamCity migration steps in migrating.md, then check the Snyk integrations and any other externally configured analysis tooling named in the issue. Done means the relevant configurations use main and a test PR is merged to main successfully.

Written by the indexing model from the issue text.