Use overlay

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

packages/docker/prometheus-podman-exporter/default.nix

@@ -1,12 +1,5 @@
-{
-  pkgs,
-  inputs,
-  system,
-  ...
-}:
+{ pkgs, ... }:
 let
-  selfPkgs = inputs.self.packages.${system};
-
   entrypoint = pkgs.writeTextFile {
     name = "entrypoint";
     executable = true;
@@ -20,9 +13,9 @@ pkgs.dockerTools.buildImage {
 
   copyToRoot = pkgs.buildEnv {
     name = "root";
-    paths = [
+    paths = with pkgs; [
       entrypoint
-      selfPkgs.prometheus-podman-exporter
+      prometheus-podman-exporter
     ];
     pathsToLink = [ "/bin" ];
   };