Use devenv instead of flake

flake.nix

@@ -1,85 +0,0 @@
-{
-  description = "Flutter";
-  inputs = {
-    nixpkgs-unstable.url = "github:NixOS/nixpkgs/master";
-    flake-utils.url = "github:numtide/flake-utils";
-  };
-  outputs =
-    {
-      self,
-      nixpkgs-unstable,
-      flake-utils,
-    }:
-    flake-utils.lib.eachDefaultSystem (
-      system:
-      let
-        pkgs = import nixpkgs-unstable {
-          inherit system;
-          config = {
-            android_sdk.accept_license = true;
-            allowUnfree = true;
-          };
-        };
-
-        androidComposition = pkgs.androidenv.composeAndroidPackages {
-          buildToolsVersions = [
-            "34.0.0"
-            "33.0.1"
-          ];
-          platformVersions = [
-            "27"
-            "28"
-            "29"
-            "30"
-            "31"
-            "32"
-            "33"
-            "34"
-            "35"
-          ];
-          abiVersions = [
-            "armeabi-v7a"
-            "arm64-v8a"
-          ];
-          includeNDK = true;
-          ndkVersions = [ "27.2.12479018" ];
-        };
-        # androidSdk = androidComposition.androidsdk;
-        androidSdk = pkgs.androidenv.androidPkgs.androidsdk;
-      in
-      {
-        devShell =
-          with pkgs;
-          mkShell {
-            ANDROID_SDK_ROOT = "${androidSdk}/libexec/android-sdk";
-            buildInputs = [
-              flutter
-              androidSdk
-              jdk17
-
-              # Needed by flutter_secure_storage
-              libsecret.dev
-              jsoncpp.dev
-
-              gtk3.dev
-              pcre2.dev
-              libsysprof-capture
-              util-linux.dev
-              libselinux.dev
-              libsepol.dev
-              libthai.dev
-              libgcrypt.dev
-              libdatrie.dev
-              libgpg-error.dev
-              xorg.libXdmcp.dev
-              lerc.dev
-              libxkbcommon.dev
-              libepoxy.dev
-              xorg.libXtst
-
-              pkg-config
-            ];
-          };
-      }
-    );
-}