Add in errors used in the beam code that were removed at some point (e…

…xplosion#11935)

I don't think there's any way to use the beam code at the moment, but as
long as it's around the errors it refers to should also be present.

spacy/errors.py

@@ -316,6 +316,11 @@ class Errors(metaclass=ErrorsWithCodes):
  "clear the existing vectors and resize the table.")
  E074 = ("Error interpreting compiled match pattern: patterns are expected "
  "to end with the attribute {attr}. Got: {bad_attr}.")
+ E079 = ("Error computing states in beam: number of predicted beams "
+ "({pbeams}) does not equal number of gold beams ({gbeams}).")
+ E080 = ("Duplicate state found in beam: {key}.")
+ E081 = ("Error getting gradient in beam: number of histories ({n_hist}) "
+ "does not equal number of losses ({losses}).")
  E082 = ("Error deprojectivizing parse: number of heads ({n_heads}), "
  "projective heads ({n_proj_heads}) and labels ({n_labels}) do not "
  "match.")