[cbuild-run] Implement multi-core support

[spcaipers-arm]

Address #1867

[github-actions]

Test Results

    3 files     18 suites   9m 30s ⏱️
  381 tests   381 ✅ 0 💤 0 ❌
1 143 runs  1 143 ✅ 0 💤 0 ❌

Results for commit a718be6.

♻️ This comment has been updated with latest results.

[codecov]

Codecov Report

Attention: Patch coverage is 82.75862% with 10 lines in your changes missing coverage. Please review.

Project coverage is 65.19%. Comparing base (724fa1f) to head (a718be6).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
tools/projmgr/src/ProjMgrRunDebug.cpp	81.81%	3 Missing and 7 partials ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1948   +/-   ##
=======================================
  Coverage   65.19%   65.19%           
=======================================
  Files         173      173           
  Lines       34922    34944   +22     
  Branches    20275    20290   +15     
=======================================
+ Hits        22766    22783   +17     
- Misses       7970     7972    +2     
- Partials     4186     4189    +3     

Flag	Coverage Δ
projmgr-cov	81.84% <82.75%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
tools/projmgr/include/ProjMgrRunDebug.h	100.00% <ø> (ø)
tools/projmgr/src/ProjMgrCbuildRun.cpp	87.67% <100.00%> (+0.52%)	⬆️
tools/projmgr/src/ProjMgrRunDebug.cpp	81.81% <81.81%> (-1.52%)	⬇️