fix: day names was wrong on the calendar page

[lukicenturi]

Closes #8088

Checklist

• The PR modified the frontend, and updated the user guide to reflect the changes.

[codecov]

Codecov Report

Attention: Patch coverage is 91.30435% with 2 lines in your changes missing coverage. Please review.

Project coverage is 53.62%. Comparing base (06ef2d3) to head (681c0ce).
Report is 6 commits behind head on develop.

Files	Patch %	Lines
...d/app/src/components/calendar/CalendarWeekdays.vue	0.00%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##           develop    #8090       +/-   ##
============================================
- Coverage    80.41%   53.62%   -26.80%     
============================================
  Files         1226     1679      +453     
  Lines       108215   166723    +58508     
  Branches     13173    13683      +510     
============================================
+ Hits         87021    89405     +2384     
- Misses       18868    74992    +56124     
  Partials      2326     2326               

Flag	Coverage Δ
frontend_integration	59.44% <0.00%> (-0.04%)	⬇️
frontend_unit	38.79% <91.30%> (-40.37%)	⬇️

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[kelsos]

lgtm