feat: Update flake to use newer Flutter

flake.nix

@@ -1,11 +1,12 @@
 {
   description = "AniTrack";
   inputs = {
-    nixpkgs.url = "github:AtaraxiaSjel/nixpkgs/update/flutter";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
     flake-utils.url = "github:numtide/flake-utils";
+    android-nixpkgs.url = "github:tadfisher/android-nixpkgs";
   };
 
-  outputs = { self, nixpkgs, flake-utils }: flake-utils.lib.eachDefaultSystem (system: let
+  outputs = { self, nixpkgs, android-nixpkgs, flake-utils }: flake-utils.lib.eachDefaultSystem (system: let
     pkgs = import nixpkgs {
       inherit system;
       config = {
@@ -13,36 +14,41 @@
         allowUnfree = true;
       };
     };
-    android = pkgs.androidenv.composeAndroidPackages {
-      # TODO: Find a way to pin these
-      #toolsVersion = "26.1.1";
-      #platformToolsVersion = "31.0.3";
-      #buildToolsVersions = [ "31.0.0" ];
-      #includeEmulator = true;
-      #emulatorVersion = "30.6.3";
-      platformVersions = [ "28" ];
-      includeSources = false;
-      includeSystemImages = true;
-      systemImageTypes = [ "default" ];
-      abiVersions = [ "x86_64" ];
-      includeNDK = false;
-      useGoogleAPIs = false;
-      useGoogleTVAddOns = false;
-    };
     pinnedJDK = pkgs.jdk17;
 
-    pythonEnv = pkgs.python3.withPackages (ps: with ps; [
-      requests pyyaml # For the build scripts
+    # Everything to make Flutter happy
+    sdk = android-nixpkgs.sdk.${system} (sdkPkgs: with sdkPkgs; [
+      cmdline-tools-latest
+      build-tools-30-0-3
+      build-tools-33-0-2
+      build-tools-34-0-0
+      platform-tools
+      emulator
+      patcher-v4
+      platforms-android-30
+      platforms-android-31
+      platforms-android-33
     ]);
   in {
     devShell = pkgs.mkShell {
       buildInputs = with pkgs; [
-        flutter pinnedJDK android.platform-tools dart scrcpy # Flutter/Android
-	      gitlint jq # Code hygiene
-      	ripgrep # General utilities
+        # Android  
+        sdk
+
+        # Flutter
+        flutter dart scrcpy pinnedJDK
+
+        # Code hygiene
+	      gitlint
       ];
 
       JAVA_HOME = pinnedJDK;
+      ANDROID_HOME = "${sdk}/share/android-sdk";
+      ANDROID_SDK_ROOT = "${sdk}/share/android-sdk";
+
+      # Fix an issue with Flutter using an older version of aapt2, which does not know
+      # an used parameter.
+      GRADLE_OPTS = "-Dorg.gradle.project.android.aapt2FromMavenOverride=${sdk}/share/android-sdk/build-tools/34.0.0/aapt2";
     };
   });
 }