Update docker.io/library/postgres Docker tag to v18.6

[red-hat-konflux]

This PR contains the following updates:

Package	Type	Update	Change
docker.io/library/postgres	final	minor	18.4 → 18.6

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Configuration

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Documentation

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 58.83%. Comparing base (ff08fb9) to head (dc030cf).
⚠️ Report is 3 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2306   +/-   ##
=======================================
  Coverage   58.83%   58.83%           
=======================================
  Files         150      150           
  Lines        9599     9599           
=======================================
  Hits         5648     5648           
  Misses       3359     3359           
  Partials      592      592           

Flag	Coverage Δ
unittests	58.83% <ø> (ø)

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