Ask HN: In the age of domain squatters, how do I correctly retire my site?

A very talented engineer I knew used to have a popular blog with some interesting projects. When he eventually got bored and shut the blog down, a cybersquatter bought it and created a spam-blog that looks exactly like the original site. His changes are subtle and it took me a few minutes to figure out that the latest post was not an honest review by the original author but an article paid by a company.

I am currently in the same situation, I have a mildly popular blog that also hosts some my FOSS projects. I plan to move everything to gitlab and shut down the blog. How can I make sure the old domain will not be an interesting target for cybersquatters? For example, can I get Google to reset my page rank?