This reverts ae0a9cb5 and therefore relands #69629.

Additionally, `flutter update-packages --force-upgrade` has been run to update `pubspec.yaml` to resolve the analyze test failures.

* update pinned null safety deps

* run update-packages

* add http dep to devicelab package

* rerun update-packages

* Roll flutter engine to a24c7c13925e4e3282f7b85814b70e63782fa057

* migrate some material files to nullsafety

* fix test_private

* address review comments

* fix private test on windows

* use uri in include entry of analysis_options

Updates all null safe dependencies to versions that allow 2.10 stable and 2.11 dev releases.

Also updates flutter_goldens and flutter_goldens_client to allow 2.11 dev.

[versions] update to latest source span and roll engine to  4b8477d11573d233e6791204191c0090f733b05d (#66136)