I'm working on a large scale project(written with Java 8 and Java 11) where they have used springfox-boot-starter.
We are working on migrating the project to Java 17 and Spring Boot 3, but facing the same issue mentioned in here Springfox Type javax.servlet.http.HttpServletRequest not present. (Even though we can add javax.servlet-api to remedy this, it will not be the desired solution for this issue as it is moved to jakarta.servlet-api)
Before moving into the springdoc-openapi-starter-webmvc-ui as an alternative, It would be ideal if we can confirm that SpringFox will not be a viable solution going forward.
The GitHub repo page, SpringFox website and the Documentation don't mention anything about the progress of this project.
Is there any official documentation mentioning that this project is discontinued or abandoned.
SpringFox is an open source project with no (current) connection to any companies or organizations1. As far as I can tell, the SpringFox website and the GitHub site that you found are the only "official" sources of information for the project. I couldn't see anything on those sites about the project being discontinued.
There don't appear to be any commits to any of the GitHub repos in the last 4 years. I would personally take that as clear evidence that in practice the project is abandoned. Others have come to the same conclusion; for example Any Springfox alternatives out there?.
However, don't just take my word for it. If this project is vital to your project, you could try to track down and talk to one of the people who were previously working on the project. (Maybe you could convince someone to update the project sites with an official project death notice.)
The other thing you could to is trawl through the recent forks listed on GitHub and reach out to the owners of any that seem promising.
On the other hand, you seem to have already identified an alternative to SpringFox, and there may be others. So maybe it is not worth your while to doing the above.
1 - There is a SpringFox company based in Melbourne, but it is in a different market: "resilience training". I doubt there is any connection.