Foundation update CVXPY 1.1.15 (#6020)
Foundation update CVXPY 1.1.15 (#6020)

- Update cvxpy python package version to latest 1.1.15. To avoid
  installation issue `error in cvxpy setup command: use_2to3 is invalid`
jameschch/Lean,AlexCatarino/Lean,QuantConnect/Lean,QuantConnect/Lean,QuantConnect/Lean,AlexCatarino/Lean,jameschch/Lean,jameschch/Lean,jameschch/Lean,JKarathiya/Lean,AlexCatarino/Lean,jameschch/Lean,AlexCatarino/Lean,JKarathiya/Lean,QuantConnect/Lean,JKarathiya/Lean,JKarathiya/Lean