Cannot unmarshal !!str `nil` into float64

[yshngg]

Encounter an error when setting the threshold to nil. The error message is: "cannot unmarshal !!str nil into float64".

The default configuration is being used, as shown below:

diff:
  # Allowed threshold for the test coverage difference (in percentage)
  # between the feature branch and the base branch.
  #
  # By default, this is disabled (set to nil). Valid values range from
  # -100.0 to +100.0.
  #
  # Example:
  #   If set to 0.5, an error will be reported if the feature branch has
  #   less than 0.5% more coverage than the base.
  #
  #   If set to -0.5, the check allows up to 0.5% less coverage than the base.
  threshold: nil