[nagios] remove deprecated monitor

[atoulme]

Description:
Remove deprecated monitor ; deprecated since August 2024.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 39.75%. Comparing base (f4cbf81) to head (e169aa8).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7099      +/-   ##
==========================================
+ Coverage   39.49%   39.75%   +0.26%     
==========================================
  Files         342      341       -1     
  Lines       23856    23697     -159     
==========================================
- Hits         9422     9421       -1     
+ Misses      13656    13499     -157     
+ Partials      778      777       -1     

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[jcatera-splunk]

The component name or one word describing the area of concern (e.g., crosslink)

[atoulme]

this is not markdown but yaml, where comments start with #. I think the confusion comes from the fact that this file is included in this PR ; this file is temporary, at release time, all files in the .chloggen folder are compacted and added neatly to the CHANGELOG.md with the right section headers.

[jcatera-splunk]

@atoulme I just had a copyedit. I guess it's a little strange having an H1 heading with sentences, too. You could either lower the heading level or shorten the headings. If neither, it's fine, too. I'm just proposing some possible improvements.