Update common.timing to make tests more deterministic

[jsiirola]

Fixes # .

Summary/Motivation:

This has some minor updates to the timing tests to make them more deterministic and hopefully resolve some intermittent test failures.

Changes proposed in this PR:

• toc() should grab the current time ASAP to avoid timing differences due to context switches while interrogating the stack
• Extend the switchinterval during timing tests to discourage context switches
• Add a missing package to the list of expected TPL imports

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.58%. Comparing base (69f1937) to head (4ad110e).
Report is 18 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3397   +/-   ##
=======================================
  Coverage   88.58%   88.58%           
=======================================
  Files         883      883           
  Lines      100289   100289           
=======================================
  Hits        88841    88841           
  Misses      11448    11448           

Flag	Coverage Δ
linux	86.04% <100.00%> (ø)
osx	76.03% <100.00%> (ø)
other	86.53% <100.00%> (-0.01%)	⬇️
win	84.38% <100.00%> (-0.01%)	⬇️

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