The solution is not as written by Mods to go to 64bit, but to fix the broken link.
We tell people to use arm64 because most people use docker and armhf is slowly being deprecated. And your solution starts to mix debian armhf packages with raspbian armhf packages. This could cause issues (and has) when the same package is updated in one repo. Raspberry Pi OS arm64 is pure Debian packages and doesn't have this risk. Your solution does satisfy the apt issues but is not the correct solution in my opinion.