drop redundant ExcludePatterns initialization

[thaJeztah]

Remove the explicit initialization of nil ExcludePatterns to an empty slice.

This normalization was introduced in moby/moby commit 62d83404 ("Pass options to chroot archive untar"):

moby/moby@62d8340

The current go-archive unpack paths no longer serialize or otherwise distinguish nil and empty slices, so the initialization is redundant.

[Copilot]

Pull request overview

This PR removes redundant normalization that converted TarOptions.ExcludePatterns from nil to an empty slice ([]string{}) in several unpack-related paths. Since the current unpack logic treats nil and empty slices equivalently (e.g., range over a nil slice is safe), the explicit initialization is unnecessary.

Changes:

• Removed ExcludePatterns nil-to-empty initialization in archive/chrootarchive unpack handlers.
• Simplified TestChrootUntarWithHugeExcludesList to pass TarOptions via a struct literal.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
diff.go	Removes redundant ExcludePatterns slice initialization in UnpackLayer.
chrootarchive/diff_unix.go	Removes redundant ExcludePatterns slice initialization in applyLayerHandler.
chrootarchive/archive.go	Removes redundant ExcludePatterns slice initialization in untarHandler.
chrootarchive/archive_test.go	Adjusts test to construct TarOptions inline while preserving behavior.
archive.go	Removes redundant ExcludePatterns slice initialization in untarHandler.

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 63.97%. Comparing base (e04f49b) to head (8bdc583).
⚠️ Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #62      +/-   ##
==========================================
- Coverage   65.75%   63.97%   -1.78%     
==========================================
  Files          42       42              
  Lines        2038     2634     +596     
==========================================
+ Hits         1340     1685     +345     
- Misses        528      777     +249     
- Partials      170      172       +2     

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