fix(castopod): Add support for HEAD requests using an nginx trick

patches/castopod.patch

@@ -266,7 +266,7 @@ new file mode 100644
 index 00000000000000..b782b548914795
 --- /dev/null
 +++ b/nixos/modules/services/audio/castopod.nix
-@@ -0,0 +1,287 @@
+@@ -0,0 +1,297 @@
 +{ config, lib, pkgs, ... }:
 +let
 +  cfg = config.services.castopod;
@@ -522,6 +522,14 @@ index 00000000000000..b782b548914795
 +          index index.php index.html;
 +        '';
 +
++        locations."@force_get" = {
++          extraConfig = ''
++            recursive_error_pages on;
++            proxy_method GET;
++            proxy_pass https://podcasts.dgnum.eu;
++          '';
++        };
++
 +        locations."^~ /${cfg.settings."media.root"}/" = {
 +          root = cfg.settings."media.storage";
 +          extraConfig = ''
@@ -536,6 +544,8 @@ index 00000000000000..b782b548914795
 +            SERVER_NAME = "$host";
 +          };
 +          extraConfig = ''
++            error_page 550 = @force_get;
++            if ($request_method = HEAD) { return 550; }
 +            fastcgi_intercept_errors on;
 +            fastcgi_index index.php;
 +            fastcgi_pass unix:${fpm.socket};