nixos/prometheus: throw a helpful error when services.prometheus.environmentFile is defined

nixos/doc/manual/from_md/release-notes/rl-2111.section.xml

@@ -1809,7 +1809,9 @@ Superuser created successfully.
           <literal>services.prometheus.environmentFile</literal> has
           been removed since it was causing
           <link xlink:href="https://github.com/NixOS/nixpkgs/issues/126083">issues</link>
-          and Prometheus now has native support for secret files.
+          and Prometheus now has native support for secret files, i.e.
+          <literal>basic_auth.password_file</literal> and
+          <literal>authorization.credentials_file</literal>.
         </para>
       </listitem>
       <listitem>

nixos/doc/manual/release-notes/rl-2111.section.md

@@ -508,7 +508,7 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - A new option `services.prometheus.enableReload` has been added which can be enabled to reload the prometheus service when its config file changes instead of restarting.
 
-- The option `services.prometheus.environmentFile` has been removed since it was causing [issues](https://github.com/NixOS/nixpkgs/issues/126083) and Prometheus now has native support for secret files.
+- The option `services.prometheus.environmentFile` has been removed since it was causing [issues](https://github.com/NixOS/nixpkgs/issues/126083) and Prometheus now has native support for secret files, i.e. `basic_auth.password_file` and `authorization.credentials_file`.
 
 - Dokuwiki now supports caddy! However
   - the nginx option has been removed, in the new configuration, please use the `dokuwiki.webserver = "nginx"` instead.

nixos/modules/services/monitoring/prometheus/default.nix

@@ -1554,6 +1554,8 @@ in
 
   imports = [
     (mkRenamedOptionModule [ "services" "prometheus2" ] [ "services" "prometheus" ])
+    (mkRemovedOptionModule [ "services" "prometheus" "environmentFile" ]
+      "It has been removed since it was causing issues (https://github.com/NixOS/nixpkgs/issues/126083) and Prometheus now has native support for secret files, i.e. `basic_auth.password_file` and `authorization.credentials_file`.")
   ];
 
   options.services.prometheus = {