Adapt to forced transformers version in some dependent libraries (#1638)

* Adapt to forced transformers version in some dependent libraries

* style

* Update __init__.py

* update requires_backends

src/diffusers/__init__.py

@@ -18,18 +18,6 @@ from .utils import (
 )
 
 
-# Make sure `transformers` is up to date
-if is_transformers_available():
-    import transformers
-
-    if is_transformers_version("<", "4.25.1"):
-        raise ImportError(
-            f"`diffusers` requires transformers >= 4.25.1 to function correctly, but {transformers.__version__} was"
-            " found in your environment. You can upgrade it with pip: `pip install transformers --upgrade`"
-        )
-else:
-    pass
-
 try:
     if not is_torch_available():
         raise OptionalDependencyNotAvailable()

src/diffusers/pipelines/stable_diffusion/__init__.py

@@ -46,7 +46,7 @@ if is_transformers_available() and is_torch_available():
     from .safety_checker import StableDiffusionSafetyChecker
 
 try:
-    if not (is_transformers_available() and is_torch_available()):
+    if not (is_transformers_available() and is_torch_available() and is_transformers_version(">=", "4.25.0")):
         raise OptionalDependencyNotAvailable()
 except OptionalDependencyNotAvailable:
     from ...utils.dummy_torch_and_transformers_objects import StableDiffusionImageVariationPipeline

src/diffusers/pipelines/versatile_diffusion/__init__.py

@@ -7,7 +7,7 @@ from ...utils import (
 
 
 try:
-    if not (is_transformers_available() and is_torch_available()):
+    if not (is_transformers_available() and is_torch_available() and is_transformers_version(">=", "4.25.0")):
         raise OptionalDependencyNotAvailable()
 except OptionalDependencyNotAvailable:
     from ...utils.dummy_torch_and_transformers_objects import (

src/diffusers/utils/import_utils.py

@@ -354,7 +354,20 @@ def requires_backends(obj, backends):
     if failed:
         raise ImportError("".join(failed))
 
-    if name in ["StableDiffusionDepth2ImgPipeline"] and is_transformers_version("<", "4.26.0.dev0"):
+    if name in [
+        "VersatileDiffusionTextToImagePipeline",
+        "VersatileDiffusionPipeline",
+        "VersatileDiffusionDualGuidedPipeline",
+        "StableDiffusionImageVariationPipeline",
+    ] and is_transformers_version("<", "4.25.0"):
+        raise ImportError(
+            f"You need to install `transformers>=4.25` in order to use {name}: \n```\n pip install"
+            " --upgrade transformers \n```"
+        )
+
+    if name in [
+        "StableDiffusionDepth2ImgPipeline",
+    ] and is_transformers_version("<", "4.26.0.dev0"):
         raise ImportError(
             f"You need to install `transformers` from 'main' in order to use {name}: \n```\n pip install"
             " git+https://github.com/huggingface/transformers \n```"