🧪 O step in Ring Polymer Langevin unit test fails

[Alexsp32]

ThermalLangevin: Error During Test at /home/runner/work/NQCDynamics.jl/NQCDynamics.jl/test/Dynamics/rpmdef.jl:53
  Got exception outside of a @test
  ArgumentError: number of inner repetitions (1) cannot be less than number of dimensions of input array (2)
  Stacktrace:
    [1] check(arr::Matrix{Float64}, inner::Int64, outer::Nothing)
      @ Base._RepeatInnerOuter ./abstractarraymath.jl:446
    [2] repeat(arr::Matrix{Float64}; inner::Int64, outer::Nothing)
      @ Base._RepeatInnerOuter ./abstractarraymath.jl:400
    [3] repeat(A::Matrix{Float64}; inner::Int64, outer::Nothing)
      @ Base ./abstractarraymath.jl:394
    [4] step_O!(friction::NQCDynamics.DynamicsMethods.IntegrationAlgorithms.LangevinCache

This may be a left-over from #349 which wasn't properly tested. Maybe need to define a behaviour for temperature in Ring-polymer simulations where vectorisation of temperature is currently unsupported.