Switch lpcnet plugin to git

pubspec.lock

@@ -778,9 +778,11 @@ packages:
   lpcnet_flutter:
     dependency: "direct main"
     description:
-      path: "../packages/lpcnet_flutter"
-      relative: true
-    source: path
+      path: "."
+      ref: main
+      resolved-ref: "39fadf011552a785993657506aedff85186b968b"
+      url: "https://github.com/dz0ny/lpcnet_flutter.git"
+    source: git
     version: "0.1.0"
   matcher:
     dependency: transitive

pubspec.yaml

@@ -52,7 +52,9 @@ dependencies:
       url: https://github.com/dz0ny/codec2_flutter.git
       ref: 03998a2
   lpcnet_flutter:
-    path: ../packages/lpcnet_flutter
+    git:
+      url: https://github.com/dz0ny/lpcnet_flutter.git
+      ref: main
   ffi: ^2.1.0
 
   # Voice recording (raw PCM stream at 8000 Hz)