When you start contributing to an open source project, you should start with tackling an open issue, or opening an issue and contributing per their process. Jumping in, opening random pull requests, forks, tagging, and trying to alter the build process is not a good way to do so. Changing the build process, which affects every single person that touches the code, and can also interact with CICD platforms you don't have access to, is possibly the worst place to jump into, especially when they don't show any interest in this.
The lack of commits for months was also a good clue that this wasn't a good place to contribute. Getting insta-banned is still weird, though. If someone makes a PR and then immediately closes it, that strongly implies human error rather than spam or any other malice. The right move is the default one: ignore it until something actually happens.
