Revert "nixos/modprobe: add boot.initrd.extraModprobeConfig option"

This reverts commit 1c58cdbeed, since this change was made redundant by 3dc6fab5c9 and in https://github.com/NixOS/nixpkgs/pull/145013 we decided to revert this commit.

nixos/doc/manual/from_md/release-notes/rl-2205.section.xml

@@ -1317,14 +1317,6 @@
           files.
         </para>
       </listitem>
-      <listitem>
-        <para>
-          A new option
-          <literal>boot.initrd.extraModprobeConfig</literal> has been
-          added which can be used to configure kernel modules that are
-          loaded in the initrd.
-        </para>
-      </listitem>
       <listitem>
         <para>
           <literal>nixos-generate-config</literal> now puts the dhcp

nixos/doc/manual/release-notes/rl-2205.section.md

@@ -491,8 +491,6 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - The option `services.duplicati.dataDir` has been added to allow changing the location of duplicati's files.
 
-- A new option `boot.initrd.extraModprobeConfig` has been added which can be used to configure kernel modules that are loaded in the initrd.
-
 - `nixos-generate-config` now puts the dhcp configuration in `hardware-configuration.nix` instead of `configuration.nix`.
 
 - ORY Kratos was updated to version 0.8.3-alpha.1.pre.0, which introduces some breaking changes:

nixos/modules/system/boot/modprobe.nix

@@ -34,23 +34,6 @@ with lib;
       type = types.lines;
     };
 
-    boot.initrd.extraModprobeConfig = mkOption {
-      default = "";
-      example =
-        ''
-          options zfs zfs_arc_max=1073741824
-        '';
-      description = ''
-        Does exactly the same thing as
-        <option>boot.extraModprobeConfig</option>, except
-        that the generated <filename>modprobe.conf</filename>
-        file is also included in the initrd.
-        This is useful for setting module options for kernel
-        modules that are loaded during early boot in the initrd.
-      '';
-      type = types.lines;
-    };
-
   };
 
 
@@ -67,9 +50,6 @@ with lib;
         '')}
         ${config.boot.extraModprobeConfig}
       '';
-    environment.etc."modprobe.d/nixos-initrd.conf".text = ''
-        ${config.boot.initrd.extraModprobeConfig}
-      '';
     environment.etc."modprobe.d/debian.conf".source = pkgs.kmod-debian-aliases;
 
     environment.etc."modprobe.d/systemd.conf".source = "${pkgs.systemd}/lib/modprobe.d/systemd.conf";

nixos/modules/system/boot/stage-1.nix

@@ -338,9 +338,6 @@ let
         { object = pkgs.writeText "mdadm.conf" config.boot.initrd.mdadmConf;
           symlink = "/etc/mdadm.conf";
         }
-        { object = config.environment.etc."modprobe.d/nixos-initrd.conf".source;
-          symlink = "/etc/modprobe.d/nixos-initrd.conf";
-        }
         { object = pkgs.runCommand "initrd-kmod-blacklist-ubuntu" {
               src = "${pkgs.kmod-blacklist-ubuntu}/modprobe.conf";
               preferLocalBuild = true;