release-1.15: Don't include excluded items in ItemBlocks

[kaovilai]

Signed-off-by: Scott Seago [email protected]

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Please add a summary of your change

Does your change fix a particular issue?

Fixes #8510

Cherrypicks #8572

Please indicate you've done the following:

• Accepted the DCO. Commits without the DCO will delay acceptance.
• Created a changelog file (make new-changelog) or comment /kind changelog-not-required on this PR.
• Updated the corresponding documentation in site/content/docs/main.

[codecov]

Codecov Report

Attention: Patch coverage is 73.33333% with 8 lines in your changes missing coverage. Please review.

Project coverage is 59.12%. Comparing base (674e397) to head (d5ef00a).
Report is 2 commits behind head on release-1.15.

Files with missing lines	Patch %	Lines
pkg/backup/backup.go	78.94%	3 Missing and 1 partial ⚠️
pkg/backup/itemblock.go	63.63%	3 Missing and 1 partial ⚠️

Additional details and impacted files

@@               Coverage Diff                @@
##           release-1.15    #8585      +/-   ##
================================================
- Coverage         59.12%   59.12%   -0.01%     
================================================
  Files               367      367              
  Lines             39128    39141      +13     
================================================
+ Hits              23136    23142       +6     
- Misses            14523    14528       +5     
- Partials           1469     1471       +2     

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