skypeforlinux: remove

Skype has been shut down in May 2025
https://web.archive.org/web/20250505132201/https://support.microsoft.com/en-us/skype/skype-is-retiring-in-may-2025-what-you-need-to-know-2a7d2501-427f-485e-8be0-2068a9f90472

Author: mjoerg

pkgs/by-name/sk/skypeforlinux/package.nix

@@ -1653,6 +1653,7 @@ mapAliases {
   shout = nodePackages.shout; # Added unknown; moved 2024-10-19
   sky = throw "'sky' has been removed because its upstream website disappeared"; # Added 2024-07-21
   SkypeExport = skypeexport; # Added 2024-06-12
+  skypeforlinux = throw "Skype has been shut down in May 2025"; # Added 2025-05-05
   slack-dark = throw "'slack-dark' has been renamed to/replaced by 'slack'"; # Converted to throw 2024-10-17
   slimerjs = throw "slimerjs does not work with any version of Firefox newer than 59; upstream ended the project in 2021. <https://slimerjs.org/faq.html#end-of-development>"; # added 2025-01-06
   slurm-llnl = slurm; # renamed July 2017