Add lidarr-cleanup-singles package and integration

- Introduced a new package `lidarr-cleanup-singles` to identify and manage duplicate single tracks in Lidarr.
- Updated `flake.nix` to include the new package in outputs and modified app definitions to support it.
- Created a new script in `src-cleanup` for the main functionality, including audio fingerprint verification.
- Added necessary dependencies and configuration in `pyproject.toml` for the new package.
- Removed unused `flake-utils` and `systems` entries from `flake.lock` to streamline the configuration.

nix/package-cleanup.nix

@@ -0,0 +1,23 @@
+{ pkgs, src }:
+
+pkgs.python3Packages.buildPythonApplication {
+  pname = "lidarr-cleanup-singles";
+  version = "1.0.0";
+  inherit src;
+  format = "pyproject";
+  nativeBuildInputs = with pkgs.python3Packages; [
+    setuptools
+  ];
+  propagatedBuildInputs = with pkgs.python3Packages; [
+    requests
+    python-dotenv
+  ];
+  buildInputs = [
+    pkgs.chromaprint
+  ];
+  meta = {
+    mainProgram = "lidarr-cleanup-singles";
+    description = "Identify duplicate single tracks in Lidarr";
+  };
+}
+