[Fixes #11817] Drop Nginx and Letsencrypt Dockerfiles

[giohappy]

Checklist

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[codecov]

Codecov Report

Merging #11818 (20656ab) into master (c1f8aad) will increase coverage by 0.00%.
Report is 13 commits behind head on master.
The diff coverage is n/a.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #11818   +/-   ##
=======================================
  Coverage   62.98%   62.98%           
=======================================
  Files         876      876           
  Lines       52571    52571           
  Branches     6609     6609           
=======================================
+ Hits        33112    33114    +2     
+ Misses      17940    17937    -3     
- Partials     1519     1520    +1