Fix deepsource: VET-V0008 Lock erroneously passed by value (internal/test, singleflight, observability)

[hlts2]

Description:

As titled

Related Issue:

Versions:

• Go Version: 1.19.2
• Docker Version: 20.10.8
• Kubernetes Version: 1.22.0
• NGT Version: 1.14.8

Checklist:

• I have read the CONTRIBUTING document and completed our CLA agreement.
• I have checked open Pull Requests for the similar feature or fixes?

Special notes for your reviewer:

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[codecov]

Codecov Report

Base: 30.54% // Head: 30.53% // Decreases project coverage by -0.01% ⚠️

Coverage data is based on head (8acb023) compared to base (331dbb2).
Patch has no changes to coverable lines.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1863      +/-   ##
==========================================
- Coverage   30.54%   30.53%   -0.02%     
==========================================
  Files         367      367              
  Lines       33828    33828              
==========================================
- Hits        10333    10328       -5     
- Misses      23081    23086       +5     
  Partials      414      414              

Impacted Files	Coverage Δ
internal/worker/queue.go	96.20% <0.00%> (-3.80%)	⬇️
internal/errgroup/group.go	94.00% <0.00%> (-1.00%)	⬇️
internal/worker/worker.go	83.07% <0.00%> (-0.77%)	⬇️
internal/core/algorithm/ngt/ngt.go	63.28% <0.00%> (-0.65%)	⬇️
pkg/agent/core/ngt/service/option.go	91.41% <0.00%> (+1.84%)	⬆️

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[cloudflare-workers-and-pages]

Deploying with    Cloudflare Pages

Latest commit:	8acb023
Status:	✅  Deploy successful!
Preview URL:	https://14ea5d7b.vald.pages.dev
Branch Preview URL:	https://refactor-vet-v0008-lock-erro-u4le.vald.pages.dev

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