tests: re-enable tun/tap test on Debian

[zyga]

This test used to fail and was disabled to unblock master but upon
inspection it does not fail anymore. The reason of the earlier failure
remains unknown.

Signed-off-by: Zygmunt Krynicki zygmunt.krynicki@canonical.com

[codecov-io]

Codecov Report

Merging #4213 into master will decrease coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #4213      +/-   ##
==========================================
- Coverage   75.83%   75.83%   -0.01%     
==========================================
  Files         439      439              
  Lines       38176    38176              
==========================================
- Hits        28952    28951       -1     
- Misses       7214     7215       +1     
  Partials     2010     2010

Impacted Files	Coverage Δ
overlord/ifacestate/helpers.go	59.6% <0%> (-0.67%)	⬇️
cmd/snap/cmd_aliases.go	95% <0%> (+1.66%)	⬆️

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