Libraries contain tests that fail probabilistically

[bamarsha]

The standard libraries contain probabilistic tests that fail occassionally in practice, which disrupts CI runs. The tests should use a fixed random seed or be disabled.

Problem tests:

TestRobustPhaseEstimation

QuantumLibraries/Standard/tests/QcvvTests.qs

Lines 103 to 105 in 6e11411

	// Probabilistic test. Might fail occasionally
	@Test("QuantumSimulator")
	operation TestRobustPhaseEstimation() : Unit {

Unhandled exception. Microsoft.Quantum.Simulation.Core.ExecutionFailException: Values were not equal within tolerance.
	Expected:	-2.6179938779914944
	Actual:	-2.629243070435989
 ---> Microsoft.Quantum.Tests.TestRobustPhaseEstimation on D:\a\1\s\submodules\QuantumLibraries\Standard\tests\QcvvTests.qs:line 109

TestEstimateFrequencyBinomial

QuantumLibraries/Standard/tests/QcvvTests.qs

Lines 60 to 63 in 6e11411

	@Test("QuantumSimulator")
	operation TestEstimateFrequencyBinomial() : Unit {
	// If this is larger, tests fail less often, but more false negatives
	// slip through.

Unhandled exception. Microsoft.Quantum.Simulation.Core.ExecutionFailException: Values were not equal within tolerance.
	Expected:	0.5153
	Actual:	0.5
 ---> Microsoft.Quantum.Tests.EstimateFrequencyBinomialCase on D:\a\1\s\submodules\QuantumLibraries\Standard\tests\QcvvTests.qs:line 57
   at Microsoft.Quantum.Tests.TestEstimateFrequencyBinomial on D:\a\1\s\submodules\QuantumLibraries\Standard\tests\QcvvTests.qs:line 65