fix(deps): update dependency file_picker to v6

packages/app/pubspec.lock

@@ -243,10 +243,10 @@ packages:
     dependency: transitive
     description:
       name: file_picker
-      sha256: be325344c1f3070354a1d84a231a1ba75ea85d413774ec4bdf444c023342e030
+      sha256: "903dd4ba13eae7cef64acc480e91bf54c3ddd23b5b90b639c170f3911e489620"
       url: "https://pub.dev"
     source: hosted
-    version: "5.5.0"
+    version: "6.0.0"
   file_selector_linux:
     dependency: transitive
     description:

packages/neon/neon/pubspec.yaml

@@ -9,7 +9,7 @@ environment:
 dependencies:
   collection: ^1.0.0
   crypto: ^3.0.0
-  file_picker: ^5.0.0
+  file_picker: ^6.0.0
   filesize: ^2.0.0
   flutter:
     sdk: flutter

packages/neon/neon_files/pubspec.yaml

@@ -12,7 +12,7 @@ dependencies:
     git:
       url: https://github.com/nextcloud/neon
       path: packages/file_icons
-  file_picker: ^5.0.0
+  file_picker: ^6.0.0
   filesize: ^2.0.0
   flutter:
     sdk: flutter