Minimise Test Execution Time

[Samyoul]

A major problem with CI test runs is the amount of time they take for a single run. 5 minute tests have become 1 hour test runs that may timeout or fail.

Investigate and implement a solution for minimising test execution time.

Potential avenues include:

• Implement Parallel CI Test Runs #5068
• Reduce CI Test Burden By Targeting Only Effected Code (Possibly Total Madness) #5069
• Introduce Test Types #4935
• Implement CI new integration test mega / validation runs #4952