treewide: Change URLs to HTTPS

Lots of URLs were HTTP redirect to HTTPS. Changed those and checked them
if there's actual content. Inspired by
https://github.com/NixOS/nixpkgs/issues/60004

pkgs/tools/filesystems/aefs/default.nix

@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ fuse ];
 
   meta = with stdenv.lib; {
-    homepage = https://nixos.org/~edolstra/aefs/;
+    homepage = https://github.com/edolstra/aefs;
     description = "A cryptographic filesystem implemented in userspace using FUSE";
     platforms = platforms.linux;
     maintainers = [ maintainers.eelco ];