Add Ray Autoscaler to the Flyte-Ray plugin

[Yicheng-Lu-llll]

Tracking issue

#4187

Describe your changes

Add Ray Autoscaler config to the Flyte-Ray plugin. See flyteorg/flytekit#1937 for motivations and detail examples.

Check all the applicable boxes

• I updated the documentation accordingly.
• All new and existing tests passed.
• All commits are signed-off.

Screenshots

Note to reviewers

[codecov]

Codecov Report

Attention: 6 lines in your changes are missing coverage. Please review.

Comparison is base (853ebe4) 59.01% compared to head (6d4f35a) 59.02%.

Files	Patch %	Lines
flyteplugins/go/tasks/plugins/k8s/ray/ray.go	66.66%	4 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4363      +/-   ##
==========================================
+ Coverage   59.01%   59.02%   +0.01%     
==========================================
  Files         622      622              
  Lines       52816    52823       +7     
==========================================
+ Hits        31169    31181      +12     
+ Misses      19156    19151       -5     
  Partials     2491     2491              

Flag	Coverage Δ
unittests	59.02% <66.66%> (+0.01%)	⬆️

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