A pity. Cirrus has been providing quite decent CI facilities, for free. One of the advantages (among many) compared to GitHub Actions is the large variety of runner images, e.g., Debian, Fedora, Alpine, FreeBSD, ...
Detailed information, paper links, and open-source code for all work discussed in this article can be found on Professor Dong's personal homepage (faculty.bicmr.pku.edu.cn/~dongbin/) and the project blog (frenzymath.com). Key links for the Anderson Conjecture solution and open-source tools are below: