Simplify soft dependencies and update the dummy-creation process (#36827)

* Reverse dependency map shouldn't be created when test_all is set

* [test_all] Remove dummies

* Modular fixes

* Update utils/check_repo.py

Co-authored-by: Pablo Montalvo <39954772+molbap@users.noreply.github.com>

* [test_all] Better docs

* [test_all] Update src/transformers/commands/chat.py

Co-authored-by: Joao Gante <joaofranciscocardosogante@gmail.com>

* [test_all] Remove deprecated AdaptiveEmbeddings from the tests

* [test_all] Doc builder

* [test_all] is_dummy

* [test_all] Import utils

* [test_all] Doc building should not require all deps

---------

Co-authored-by: Pablo Montalvo <39954772+molbap@users.noreply.github.com>
Co-authored-by: Joao Gante <joaofranciscocardosogante@gmail.com>

tests/test_modeling_common.py

@@ -119,7 +119,7 @@ if is_torch_available():
     from safetensors.torch import save_file as safe_save_file
     from torch import nn
 
-    from transformers import MODEL_MAPPING, AdaptiveEmbedding
+    from transformers import MODEL_MAPPING
     from transformers.cache_utils import Cache, DynamicCache
     from transformers.modeling_utils import load_state_dict, no_init_weights
     from transformers.pytorch_utils import id_tensor_storage
@@ -2095,7 +2095,7 @@ class ModelTesterMixin:
 
         for model_class in self.all_model_classes:
             model = model_class(config)
-            self.assertIsInstance(model.get_input_embeddings(), (nn.Embedding, AdaptiveEmbedding))
+            self.assertIsInstance(model.get_input_embeddings(), nn.Embedding)
 
             new_input_embedding_layer = nn.Embedding(10, 10)
             model.set_input_embeddings(new_input_embedding_layer)