fix: do not multithread ChatMessage processing

[TestingPlant]

Chat messages must be processed before the packet bump allocator is cleared because they store a reference to the packet data. In other words, we need a happens-before relationship where chat message processing happens before the packet bump allocator is cleared. Disabling multithreaded ChatMessage processing is one way of providing this happens-before relationship, and since processing chat messages is relatively cheap, this should not cause any noticable performance problems.

[github-actions]

Benchmark Results for general

ray_intersection/aabb_size_0.1                     [  19.3 ns ...  19.3 ns ]      -0.41%
ray_intersection/aabb_size_1                       [  19.2 ns ...  19.3 ns ]      +0.20%
ray_intersection/aabb_size_10                      [  19.3 ns ...  19.2 ns ]      -0.18%
ray_intersection/ray_distance_1                    [   3.8 ns ...   3.8 ns ]      +0.16%
ray_intersection/ray_distance_5                    [   3.9 ns ...   3.9 ns ]      -0.03%
ray_intersection/ray_distance_20                   [   3.8 ns ...   3.8 ns ]      -0.05%
overlap/no_overlap                                 [  28.7 ns ...  28.7 ns ]      -0.11%
overlap/partial_overlap                            [  28.8 ns ...  28.7 ns ]      -0.22%
overlap/full_containment                           [  21.4 ns ...  21.6 ns ]      +1.02%
point_containment/inside                           [   4.9 ns ...   4.9 ns ]      +0.40%
point_containment/outside                          [   4.5 ns ...   4.4 ns ]      -0.15%
point_containment/boundary                         [   7.5 ns ...   7.6 ns ]      +0.90%

Comparing to 7c99a55

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 21.01%. Comparing base (7c99a55) to head (ea8806b).
Report is 16 commits behind head on main.

@@           Coverage Diff           @@
##             main     #861   +/-   ##
=======================================
  Coverage   21.00%   21.01%           
=======================================
  Files         160      160           
  Lines       16902    16901    -1     
  Branches      470      470           
=======================================
  Hits         3551     3551           
+ Misses      13285    13284    -1     
  Partials       66       66           

Files with missing lines	Coverage Δ
events/tag/src/module/chat.rs	0.00% <ø> (ø)

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[andrewgazelka]

I'm not sure I like the current way you're handling this. In an ideal world, you would have a sync point, not just making this multithreaded. I think there should be a sync point between when all of the events end and when the bump allocator is cleared.

[TestingPlant]

Replaced with #888