Run unit tests on master for code coverage reports

[RoiEXLab]

This is a partial revert of #8257
The codecov coverage is completely messed up because there no longer are reports from master, so the diff says nothing really making it useless.
This change restores the "old" behaviour for unit tests so that the reports make sense now.

EDIT: actually we only need builds when pushing to master, so I added that in

[RoiEXLab]

/cc @DanVanAtta

[codecov]

Codecov Report

Merging #8594 (df858a3) into master (a7a7576) will increase coverage by 0.06%.
The diff coverage is 23.42%.

@@             Coverage Diff              @@
##             master    #8594      +/-   ##
============================================
+ Coverage     24.83%   24.90%   +0.06%     
- Complexity     7304     7371      +67     
============================================
  Files          1265     1288      +23     
  Lines         79592    80308     +716     
  Branches      11085    11013      -72     
============================================
+ Hits          19765    19999     +234     
- Misses        57754    58240     +486     
+ Partials       2073     2069       -4     

Impacted Files	Coverage Δ	Complexity Δ
...ava/org/triplea/ai/does/nothing/DoesNothingAi.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)
...triplea/ai/does/nothing/DoesNothingAiProvider.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)
.../main/java/org/triplea/ai/flowfield/Constants.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)
...ain/java/org/triplea/ai/flowfield/FlowFieldAi.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)
.../org/triplea/ai/flowfield/FlowFieldAiProvider.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)
...ea/ai/flowfield/influence/InfluenceMapBuilder.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)
.../triplea/ai/flowfield/influence/ResourceValue.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)
...a/ai/flowfield/influence/TerritoryDebugAction.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)
...field/influence/defense/AllyResourceToProtect.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)
...owfield/influence/defense/MyResourceToProtect.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)
... and 460 more

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