Fix a grammatical error in the `raise` messages (#8272)

Fix grammatical error

src/diffusers/schedulers/scheduling_lcm.py

@@ -224,7 +224,7 @@ class LCMScheduler(SchedulerMixin, ConfigMixin):
             # Glide cosine schedule
             self.betas = betas_for_alpha_bar(num_train_timesteps)
         else:
-            raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
+            raise NotImplementedError(f"{beta_schedule} is not implemented for {self.__class__}")
 
         # Rescale for zero SNR
         if rescale_betas_zero_snr:

src/diffusers/schedulers/scheduling_lms_discrete.py

@@ -149,7 +149,7 @@ class LMSDiscreteScheduler(SchedulerMixin, ConfigMixin):
             # Glide cosine schedule
             self.betas = betas_for_alpha_bar(num_train_timesteps)
         else:
-            raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
+            raise NotImplementedError(f"{beta_schedule} is not implemented for {self.__class__}")
 
         self.alphas = 1.0 - self.betas
         self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)

src/diffusers/schedulers/scheduling_pndm.py

@@ -135,7 +135,7 @@ class PNDMScheduler(SchedulerMixin, ConfigMixin):
             # Glide cosine schedule
             self.betas = betas_for_alpha_bar(num_train_timesteps)
         else:
-            raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
+            raise NotImplementedError(f"{beta_schedule} is not implemented for {self.__class__}")
 
         self.alphas = 1.0 - self.betas
         self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)

src/diffusers/schedulers/scheduling_repaint.py

@@ -143,7 +143,7 @@ class RePaintScheduler(SchedulerMixin, ConfigMixin):
             betas = torch.linspace(-6, 6, num_train_timesteps)
             self.betas = torch.sigmoid(betas) * (beta_end - beta_start) + beta_start
         else:
-            raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
+            raise NotImplementedError(f"{beta_schedule} is not implemented for {self.__class__}")
 
         self.alphas = 1.0 - self.betas
         self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)

src/diffusers/schedulers/scheduling_sasolver.py

@@ -180,7 +180,7 @@ class SASolverScheduler(SchedulerMixin, ConfigMixin):
             # Glide cosine schedule
             self.betas = betas_for_alpha_bar(num_train_timesteps)
         else:
-            raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
+            raise NotImplementedError(f"{beta_schedule} is not implemented for {self.__class__}")
 
         self.alphas = 1.0 - self.betas
         self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
@@ -194,7 +194,7 @@ class SASolverScheduler(SchedulerMixin, ConfigMixin):
         self.init_noise_sigma = 1.0
 
         if algorithm_type not in ["data_prediction", "noise_prediction"]:
-            raise NotImplementedError(f"{algorithm_type} does is not implemented for {self.__class__}")
+            raise NotImplementedError(f"{algorithm_type} is not implemented for {self.__class__}")
 
         # setable values
         self.num_inference_steps = None

src/diffusers/schedulers/scheduling_tcd.py

@@ -225,7 +225,7 @@ class TCDScheduler(SchedulerMixin, ConfigMixin):
             # Glide cosine schedule
             self.betas = betas_for_alpha_bar(num_train_timesteps)
         else:
-            raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
+            raise NotImplementedError(f"{beta_schedule} is not implemented for {self.__class__}")
 
         # Rescale for zero SNR
         if rescale_betas_zero_snr:

src/diffusers/schedulers/scheduling_unipc_multistep.py

@@ -211,7 +211,7 @@ class UniPCMultistepScheduler(SchedulerMixin, ConfigMixin):
             # Glide cosine schedule
             self.betas = betas_for_alpha_bar(num_train_timesteps)
         else:
-            raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
+            raise NotImplementedError(f"{beta_schedule} is not implemented for {self.__class__}")
 
         if rescale_betas_zero_snr:
             self.betas = rescale_zero_terminal_snr(self.betas)
@@ -237,7 +237,7 @@ class UniPCMultistepScheduler(SchedulerMixin, ConfigMixin):
             if solver_type in ["midpoint", "heun", "logrho"]:
                 self.register_to_config(solver_type="bh2")
             else:
-                raise NotImplementedError(f"{solver_type} does is not implemented for {self.__class__}")
+                raise NotImplementedError(f"{solver_type} is not implemented for {self.__class__}")
 
         self.predict_x0 = predict_x0
         # setable values