Release notes for 551

ScriptProfiler: starting a new profiling session resets previously collected profiling data.

ScriptProfiler: fix an issue where large amounts of time were incorrectly attributed to event handlers that are executed under an Actor

Fix for hidden purchase during game pause.

Improved the wording of an error message when unifying Luau type packs.

Fixed disabled particles affecting particle updates

Fix Toolbox scrolling bug on Categories such as Materials and Dev Modules.