Remove PR-Status badges from README

[piponazo]

I noticed that in the main documentation page we were showing some badges about the CI status in Pull Requests.

This might send a wrong message to users regarding the status of the project.

I also took the opportunity to try to reduce the CI workload when only modifying *.md files.

[piponazo]

Note that at the moment the CI jobs are still running because in this PR there are also changes in the *.yml files

[codecov]

Codecov Report

Merging #2098 (18ba4e5) into main (e450c49) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #2098   +/-   ##
=======================================
  Coverage   63.19%   63.19%           
=======================================
  Files          96       96           
  Lines       19203    19203           
  Branches     9797     9797           
=======================================
  Hits        12135    12135           
  Misses       4762     4762           
  Partials     2306     2306           

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