Replace Flasgger library
Flasgger, along with a few other libraries, are used to generate and serve our OpenAPI (swagger) documentation. The library has an issue that makes it unsuitable for hosting multiple doc pages at once which we use whenever we are deprecating endpoints and migrating to a new router version. There has been an issue and associated PR for months that have not been updated. https://github.com/flasgger/flasgger/pull/573
Research into a suitable replacement should be made. If there is a suitable replacement available, it should be implemented.