palemoon: Drop

It has Python 2.x as a build-time dependency, which has been EOL for years and was finally marked as insecure in #201859.
As such, it has been unbuildable on master without enabling insecure packages for almost half a year.

Upstream has no plans to migrate their build system away from py2 (though they might accept help with it), so we'll have to drop it:
https://forum.palemoon.org/viewtopic.php?f=62&t=28863&p=232152

pkgs/top-level/aliases.nix

@@ -1203,6 +1203,7 @@ mapAliases ({
 
   p11_kit = throw "'p11_kit' has been renamed to/replaced by 'p11-kit'"; # Converted to throw 2022-02-22
   packet-cli = metal-cli; # Added 2021-10-25
+  palemoon = throw "palemoon has been dropped due to python2 being EOL and marked insecure. Use 'palemoon-bin' instead"; # Added 2023-05-18
   paperless = paperless-ngx; # Added 2021-06-06
   paperless-ng = paperless-ngx; # Added 2022-04-11
   paper-note = throw "paper-note has been removed: abandoned by upstream"; # Added 2023-05-03

pkgs/top-level/all-packages.nix

@@ -33199,7 +33199,6 @@ with pkgs;
 
   osmscout-server = libsForQt5.callPackage ../applications/misc/osmscout-server { };
 
-  palemoon = callPackage ../applications/networking/browsers/palemoon { };
   palemoon-bin = callPackage ../applications/networking/browsers/palemoon/bin.nix { };
 
   paleta = callPackage ../applications/graphics/paleta { };