Stream contains an occurrence even though the start time should have filtered it out

[marcojulian]

When creating a schedule without a recurrence rule, the occurrence is in the sequence even if the start time passed to occurrences/2 is later than the start time passed to new/2.

iex> schedule = Cocktail.Schedule.new(~U[2025-02-10 00:00:00Z])
#Cocktail.Schedule<>
iex> schedule |> Cocktail.Schedule.occurrences |> Enum.take(1)
[~U[2025-02-10 00:00:00Z]]
iex> schedule |> Cocktail.Schedule.occurrences(~U[2025-02-15 00:00:00Z]) |> Enum.take(1)
[~U[2025-02-10 00:00:00Z]]

Expected result:

iex> schedule = Cocktail.Schedule.new(~U[2025-02-10 00:00:00Z])
#Cocktail.Schedule<>
iex> schedule |> Cocktail.Schedule.occurrences |> Enum.take(1)
[~U[2025-02-10 00:00:00Z]]
iex> schedule |> Cocktail.Schedule.occurrences(~U[2025-02-15 00:00:00Z]) |> Enum.take(1)
[]