pkg/pillar: skip TestPciLongExists in unit tests

[shjala]

Description

The TestPciLongExists unit test relies on the presence of specific PCI devices (e.g., 0000:00:00.0) on the host system running the tests. This causes failures in CI environments or on non-x86 architectures where such devices may not exist or be accessible.

This change skips the test to avoid false negatives.

PR dependencies

None

How to test and validate this PR

N/A/

Changelog notes

N/A.

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[eriknordmark]

LGTM

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 28.32%. Comparing base (2281599) to head (9b7cc85).
⚠️ Report is 256 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5583      +/-   ##
==========================================
+ Coverage   19.52%   28.32%   +8.79%     
==========================================
  Files          19       18       -1     
  Lines        3021     2256     -765     
==========================================
+ Hits          590      639      +49     
+ Misses       2310     1475     -835     
- Partials      121      142      +21     

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[rene]

@shjala , please, provide the backport of this PR to 16.0-stable. Go-tests are broken on this branch.