zabbix64: remove due to EOL

zabbix64 is EOL.

https://www.zabbix.com/life_cycle_and_release_policy

pkgs/servers/monitoring/zabbix/versions.nix

···
     hash = "sha256-r9VNy3bRuFvJAL+ZQEbKjCAS3+AvetnWAwFjLxFVuGU=";
     vendorHash = null;
   };
-  v64 = generic {
-    version = "6.4.20";
-    hash = "sha256-tFsg2Jq8Uaa5YULGUu1kXLkxyJuA3YGeSfJ4DPfOHkk=";
-    vendorHash = null;
-  };
   v60 = generic {
     version = "6.0.36";
     hash = "sha256-Ne0OY6NGzTYOn3sDVd+5tfawBu5VBjxNRtlxasubGCk=";

pkgs/top-level/aliases.nix

···
   ### Z ###
 
   zabbix50 = throw "'zabbix50' has been removed, it would have reached its End of Life a few days after the release of NixOS 25.05. Consider upgrading to 'zabbix60' or 'zabbix70'.";
+  zabbix64 = throw "'zabbix64' has been removed because it reached its End of Life. Consider upgrading to 'zabbix70'.";
   zeroadPackages = recurseIntoAttrs {
     zeroad = lib.warnOnInstantiate "'zeroadPackages.zeroad' has been renamed to 'zeroad'" zeroad; # Added 2025-03-22
     zeroad-data = lib.warnOnInstantiate "'zeroadPackages.zeroad-data' has been renamed to 'zeroad-data'" zeroad-data; # Added 2025-03-22

pkgs/top-level/all-packages.nix

···
   zabbix72 = recurseIntoAttrs (zabbixFor "v72");
   zabbix70 = recurseIntoAttrs (zabbixFor "v70");
   zabbix60 = recurseIntoAttrs (zabbixFor "v60");
-  zabbix64 = recurseIntoAttrs (zabbixFor "v64");
 
   zabbix = zabbix60;