Fix #6752: add namespace exclude check.

[blackpiglet]

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Fix #6752
Add the namespace exclude check to avoid all namespaces listed in the backup.
Also, add the PSA warning and audit label to avoid prompting warning messages and audit events.

Does your change fix a particular issue?

Fixes #(issue)

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• Accepted the DCO. Commits without the DCO will delay acceptance.
• Created a changelog file or added /kind changelog-not-required as a comment on this pull request.
• Updated the corresponding documentation in site/content/docs/main.

[codecov]

Codecov Report

Merging #6760 (79b810e) into main (8d3a675) will increase coverage by 0.08%.
Report is 7 commits behind head on main.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #6760      +/-   ##
==========================================
+ Coverage   60.33%   60.41%   +0.08%     
==========================================
  Files         242      242              
  Lines       25992    26023      +31     
==========================================
+ Hits        15681    15721      +40     
+ Misses       9205     9197       -8     
+ Partials     1106     1105       -1     

Files Changed	Coverage Δ
pkg/backup/item_collector.go	57.87% <100.00%> (-0.48%)	⬇️
pkg/install/resources.go	77.20% <100.00%> (-0.58%)	⬇️

... and 7 files with indirect coverage changes