koordlet: avoid create multi nri connection

[yyrdl]

Ⅰ. Describe what this PR does

解决 nri server 重连时有概率导致创建大量 nri 链接的问题, 这会产生两个风险:

• containerd 将多个 nri 链接认为是多个 plugin ，发现多个plugin 修改同一个字段，导致创建容器失败
• onClose callback 的设计会导致创建大量 goroutine ，在携程的使用过程中，观测到创建了 1000多万个 goroutine ,进而导致 OOM

Ⅱ. Does this pull request fix one issue?

fixes #2334

Ⅲ. Describe how to verify it

线上场景不好构造，check 同步提交的单测吧

Ⅳ. Special notes for reviews

V. Checklist

• I have written necessary docs and comments
• I have added necessary unit tests and integration tests
• All checks passed in make test

[codecov]

Codecov Report

❌ Patch coverage is 70.04049% with 74 lines in your changes missing coverage. Please review.
✅ Project coverage is 66.46%. Comparing base (614ee0d) to head (c4674e3).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/koordlet/runtimehooks/nri/server.go	72.80%	26 Missing and 5 partials ⚠️
pkg/koordlet/runtimehooks/nri/handlers.go	68.67%	20 Missing and 6 partials ⚠️
pkg/koordlet/runtimehooks/nri/mock_nri.go	60.46%	17 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2617      +/-   ##
==========================================
+ Coverage   66.43%   66.46%   +0.02%     
==========================================
  Files         487      490       +3     
  Lines       58812    58914     +102     
==========================================
+ Hits        39074    39158      +84     
- Misses      16892    16903      +11     
- Partials     2846     2853       +7     

Flag	Coverage Δ
unittests	66.46% <70.04%> (+0.02%)	⬆️

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[saintube]

/lgtm
/approve

[koordinator-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: saintube

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