fix(ai): complete retryable sessions after current request

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What does this pull request do? Explain your changes. (required)

Update processAIRequest to add sessions back to selector after the current request if errors are retryable.

Replaces #3400 and includes update for LiveVideoToVideo in #3407.

Specific updates (required)

• Adds sessions that have retryable errors to list to call Complete on when the request ends. LiveVideoToVideo will add insufficient capacity errors back to selector on next refresh

How did you test each of these updates (required)

Built docker image and sent batch AI request until 503 unavailable error returned. Pulled /getAISessionPoolsInfo to confirm 1 orchestrator not suspended

Does this pull request close any open issues?

No

Checklist:

• Read the contribution guide
• make runs successfully
• All tests in ./test.sh pass
• README and other documentation updated
• Pending changelog updated

[codecov]

Codecov Report

Attention: Patch coverage is 52.38095% with 10 lines in your changes missing coverage. Please review.

Project coverage is 32.09666%. Comparing base (3765073) to head (91d5786).
Report is 6 commits behind head on master.

Files with missing lines	Patch %	Lines
server/ai_process.go	52.38095%	10 Missing ⚠️

Additional details and impacted files

@@                 Coverage Diff                 @@
##              master       #3414         +/-   ##
===================================================
+ Coverage   32.08870%   32.09666%   +0.00796%     
===================================================
  Files            147         147                 
  Lines          40949       40970         +21     
===================================================
+ Hits           13140       13150         +10     
- Misses         27032       27043         +11     
  Partials         777         777                 

Files with missing lines	Coverage Δ
server/ai_process.go	1.48026% <52.38095%> (+0.89449%)	⬆️

... and 1 file with indirect coverage changes

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Files with missing lines	Coverage Δ
server/ai_process.go	1.48026% <52.38095%> (+0.89449%)	⬆️

... and 1 file with indirect coverage changes

[leszko]

Added 2 inline comments. Other than that, LGTM

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@leszko updates are complete. Should be good to merge when checks complete.