This adds avoid_dynamic_calls to the list of lints, and fixes all instances where it was violated.

Importantly, this lint is NOT turned on for flutter/packages/test, because those changes are happening in another PR: #84478

* Add 'v' hotkey to open DevTools in the browser

This reverts commit 35ad43f2.

This reverts commit c26ed03c.

* Migrate to ChannelBuffers.push

* Move TestDefaultBinaryMessenger to its own file

* Apply deprecations and fix usages

This reverts commit 2d9a01a8.

In principle this is backwards compatible; I just merged all the classes into one and deprecated everything that became redundant as a result.

This reverts commit 8749d955.

In principle this is backwards compatible; I just merged all the classes into one and deprecated everything that became redundant as a result.

* update pinned null safety deps

* run update-packages

* add http dep to devicelab package

* rerun update-packages

Force opt-in flutter test platform to null safety for repo testing