Disable feedback when typing password at a sudo prompt

I found this in another thread and it ensures that, if the Mint devs reintroduce this bad feature in a new update, your own modifications will override it:

The accepted answer of simply removing /etc/sudoers.d/0pwfeedback will work precisely until the next update to mintsystem puts that file back in place.

The way to revert to the old behavior, that is recommended by the person responsible for the new one, is to override the setting in a different file that gets read later:

echo 'Defaults !pwfeedback'|sudo tee /etc/sudoers.d/9_no_pwfeedback

Source: https://unix.stackexchange.com/questions/491173/linux-mint-how-to-set-the-terminal-password-to-be-invisible

After some more research on files in the /etc/sudoers.d directory, I found the right answer here:

Linux Mint. How to set the terminal password to be invisible?

It says:

LinuxMint added the behavior in /etc/sudoers.d/0pwfeedback.
You could simply do like I did - delete the file as it contains only that adjustment:

sudo rm -rf /etc/sudoers.d/0pwfeedback

According to @SyntaxxxErr0r, renaming the file works as well: if it ends with a ~ or contains a . character, it will not be parsed.

Recently, @elsewhere suggested another solution which is more future-proof and stable across package updates and therefore I select that answer as the most helpful.