mullvad-browser: 15.0.12 -> 15.0.14

Changelog: https://gitlab.torproject.org/tpo/applications/tor-browser-build/-/raw/mb-15.0.14-build1/projects/browser/Bundle-Data/Docs-MB/ChangeLog.txt
Firefox ESR: https://www.firefox.com/en-US/firefox/140.11.0/releasenotes/

Mullvad Browser 15.0.13 was skipped upstream as it was a Tor Browser-only release that included no Firefox changes.

pkgs/by-name/mu/mullvad-browser/package.nix

@@ -97,7 +97,7 @@ let
     ++ lib.optionals mediaSupport [ ffmpeg_7 ]
   );
 
-  version = "15.0.12";
+  version = "15.0.14";
 
   sources = {
     x86_64-linux = fetchurl {
@@ -109,7 +109,7 @@ let
         "https://tor.eff.org/dist/mullvadbrowser/${version}/mullvad-browser-linux-x86_64-${version}.tar.xz"
         "https://tor.calyxinstitute.org/dist/mullvadbrowser/${version}/mullvad-browser-linux-x86_64-${version}.tar.xz"
       ];
-      hash = "sha256-Tqfa9f2q4bv2KpotoDKvklEmHa5AF4ARp/qKxlVBomE=";
+      hash = "sha256-E/q2wXeTGcEhiAvUCrFKv34gc4vP4o3ZPjqkcS6Dxgk=";
     };
   };