conditionally enable ipv6 listen directives in nginx configs

[msc-xdev]

Enable ipv6 according to config file

Harbor has added the ability to configure external ipv6 since a3e1b1e, but has only added it to the https-side of the proxy.
Therefore a curl -LI6 http://my-harbor.tld returns:
curl: (7) Failed to connect to my-harbor.tld port 80 after 6 ms: Couldn't connect to server

This PR tries to fix that by adding it to the other listen directives in the nginx configs.

Related #11399

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• Well Written Title and Summary of the PR
• Label the PR as needed. "release-note/ignore-for-release, release-note/new-feature, release-note/update, release-note/enhancement, release-note/community, release-note/breaking-change, release-note/docs, release-note/infra, release-note/deprecation"
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• Made sure tests are passing and test coverage is added if needed.
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[msc-xdev]

I need to say that I added the ipv6 network manually in my docker-compose.yml so that the nginx sees the correct ipv6 and can log it correctly.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 46.20%. Comparing base (c8c11b4) to head (5ef2853).
Report is 268 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #20880      +/-   ##
==========================================
+ Coverage   45.36%   46.20%   +0.83%     
==========================================
  Files         244      247       +3     
  Lines       13333    13782     +449     
  Branches     2719     2847     +128     
==========================================
+ Hits         6049     6368     +319     
- Misses       6983     7084     +101     
- Partials      301      330      +29     

Flag	Coverage Δ
unittests	46.20% <ø> (+0.83%)	⬆️

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