mkcert install fails to install in firefox / chrome db on Ubuntu 20.04.

## Environment

* Operating system (including version): Ubuntu 20.04
* mkcert version (from `mkcert -version`): v1.4.3
* Server (where the certificate is loaded): ?
* Client (e.g. browser, CLI tool, or script): Firefox/Chrome

## What you did

This seems to be a consistent problem with Ubuntu, multiple computers, fresh installs even a co-worker using Ubuntu 22.04. I have installed the required dependencies. We did install from the pre-build binaries.

1. ran `mkcert -install`
2. Tried `sudo mkcert -install` - It installs, but fails to find the chrome/firefox stores.
3. Tried uninstall / reinstall

```
$ mkcert -install
The local CA is now installed in the system trust store! ⚡️
Installing in Firefox and/or Chrome/Chromium failed. Please report the issue with details about your environment at https://github.com/FiloSottile/mkcert/issues/new 👎
Note that if you never started Firefox and/or Chrome/Chromium, you need to do that at least once.

```