enhancement(sysadvisor): update region info atomically

[cheney-lin]

What type of PR is this?

Enhancements

What this PR does / why we need it:

Which issue(s) this PR fixes:

Special notes for your reviewer:

[codecov]

Codecov Report

Attention: 9 lines in your changes are missing coverage. Please review.

Comparison is base (11942ce) 53.59% compared to head (5159d38) 53.28%.
Report is 4 commits behind head on main.

Files	Patch %	Lines
...sor/plugin/qosaware/resource/cpu/advisor_helper.go	68.42%	4 Missing and 2 partials ⚠️
...assembler/headroomassembler/assembler_dedicated.go	50.00%	1 Missing and 1 partial ⚠️
...sadvisor/plugin/qosaware/resource/helper/helper.go	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #358      +/-   ##
==========================================
- Coverage   53.59%   53.28%   -0.31%     
==========================================
  Files         437      437              
  Lines       48147    48149       +2     
==========================================
- Hits        25803    25655     -148     
- Misses      19442    19597     +155     
+ Partials     2902     2897       -5     

Flag	Coverage Δ
unittest	53.28% <67.85%> (-0.31%)	⬇️

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