test: find second interface to use for mac address match

[richm]

Some systems do not use the ethN interface naming scheme, and
use ensN instead. The test wants to use eth1 as the second
interface. If this does not exist, try ens4 instead.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 43.25%. Comparing base (1b57520) to head (2b23a83).
Report is 12 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #779      +/-   ##
==========================================
+ Coverage   43.11%   43.25%   +0.13%     
==========================================
  Files          12       12              
  Lines        3124     3121       -3     
==========================================
+ Hits         1347     1350       +3     
+ Misses       1777     1771       -6     

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[richm]

fedora 42 tests are hanging on tests_mac_address_match - can reproduce locally - debugging

[richm]

Will fix one of the f42 issues in a separate commit.