Migrate to Flutter 2.6.0

[mersadcc]

When I try to build using Flutter 2.6.0+, I get this error:

Error: Too few positional arguments: 3 required, 2 given.
../…/lib/flutter_reorderable_list.dart:740
      : super(initialPosition, kind) {
             ^

FAILURE: Build failed with an exception.

[mehrdad-shokri]

can we publish an update since this pr is merged?

[Tomucha]

cc @knopp

[knopp]

I published 1.2.0. Apologies for the delay.

[Tomucha]

Thanks! Apologies for the subtle pressure :-)