Remove makedeb listing from README.md

The MPR [listing](https://mpr.makedeb.org/packages/freetube-bin) should be removed as a method to install via Linux, due to the `makedeb` [project](https://www.makedeb.org/) being [declared unmaintained](https://hunterwittenborn.com/blog/stepping-back-from-open-source/) on November 21, 2025.

Author: taivlam

README.md

@@ -127,8 +127,6 @@ The first build with a green check mark is the latest build.
 
 * Homebrew Formulae (Mac only): [Download for Apple Silicon](https://github.com/PikachuEXE/homebrew-FreeTube)
 
-* makedeb Package Repository (MPR): [Download](https://mpr.makedeb.org/packages/freetube-bin)
-
 * Nix Packages: [Download](https://search.nixos.org/packages?query=freetube)
 
 * PortableApps (Windows Only): [Download](https://github.com/rddim/FreeTubePortable/releases) and [Source Code](https://github.com/rddim/FreeTubePortable)