fix cache manager panic in yurthub

[rambohe-ch]

What type of PR is this?

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/kind bug
/kind documentation
/kind enhancement
/kind good-first-issue
/kind feature
/kind question
/kind design
/sig ai
/sig iot
/sig network
/sig storage

/kind bug

What this PR does / why we need it:

background:

yurt-hub-cfg configmap is used in multiple places, like:

• https://github.com/openyurtio/openyurt/blob/master/pkg/yurthub/cachemanager/cache_agent.go#L72
• https://github.com/openyurtio/openyurt/blob/master/pkg/yurthub/filter/approver.go#L126

In the cache manager, configmap is read, but in the approver, configmap is modified, so a panic maybe triggered.

solution:

deepcopy configmap before modify to avoid panic.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?

other Note

[sonarcloud]

Quality Gate passed

Issues
0 New issues

Measures
0 Security Hotspots
No data about Coverage
0.1% Duplication on New Code

See analysis details on SonarCloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (3e5d8fc) 52.04% compared to head (3de0034) 52.34%.
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1950      +/-   ##
==========================================
+ Coverage   52.04%   52.34%   +0.30%     
==========================================
  Files         174      173       -1     
  Lines       21213    21012     -201     
==========================================
- Hits        11040    10999      -41     
+ Misses       9199     9062     -137     
+ Partials      974      951      -23     

Flag	Coverage Δ
unittests	52.34% <100.00%> (+0.30%)	⬆️

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[YTGhost]

/lgtm

[rambohe-ch]

/backport release-v1.4

[github-actions]

Successfully created backport PR for release-v1.4:

• [Backport release-v1.4] fix cache manager panic in yurthub #1951