ci: reduce nb running jobs

[Borda]

When there is created PR from the main repo, it runs two events, push to a beach and PR, which are basically the same jobs as linear history is required... so specify target branch will run jobs on master as it is puch to master and PR accordingly...
Effectively it runs half jobs harch notification event and faster iteration dues to limited number of agent for free projects 🐿️

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (4156730) 99.41% compared to head (9bc277f) 99.41%.
Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #159   +/-   ##
=======================================
  Coverage   99.41%   99.41%           
=======================================
  Files           5        5           
  Lines         513      513           
  Branches       87       87           
=======================================
  Hits          510      510           
  Misses          2        2           
  Partials        1        1           

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