[GPTQ, CompressedTensors] Fix unsafe imports and metada check (#34815)

* fix gptq creation when optimum is not installed + fix metadata checking

* fix compressed tensors as well

* style

* pray for ci luck on flaky tests :prayge:

* trigger ci

---------

Co-authored-by: Marc Sun <57196510+SunMarc@users.noreply.github.com>
Co-authored-by: Mohamed Mekkouri <93391238+MekkCyber@users.noreply.github.com>

src/transformers/quantizers/quantizer_compressed_tensors.py

@@ -37,6 +37,13 @@ class CompressedTensorsHfQuantizer(HfQuantizer):
 
     def __init__(self, quantization_config: CompressedTensorsConfig, **kwargs):
         super().__init__(quantization_config, **kwargs)
+
+        if not is_compressed_tensors_available():
+            raise ImportError(
+                "Using `compressed_tensors` quantized models requires the compressed-tensors library: "
+                "`pip install compressed-tensors`"
+            )
+
         from compressed_tensors.compressors import ModelCompressor
 
         self.compressor = ModelCompressor.from_compression_config(quantization_config)

src/transformers/quantizers/quantizer_gptq.py

@@ -44,18 +44,25 @@ class GptqHfQuantizer(HfQuantizer):
 
     def __init__(self, quantization_config: QuantizationConfigMixin, **kwargs):
         super().__init__(quantization_config, **kwargs)
+
+        if not is_optimum_available():
+            raise ImportError("Loading a GPTQ quantized model requires optimum (`pip install optimum`)")
         from optimum.gptq import GPTQQuantizer
 
         self.optimum_quantizer = GPTQQuantizer.from_dict(self.quantization_config.to_dict_optimum())
 
     def validate_environment(self, *args, **kwargs):
+        if not is_optimum_available():
+            raise ImportError("Loading a GPTQ quantized model requires optimum (`pip install optimum`)")
+
+        if not is_auto_gptq_available():
+            raise ImportError(
+                "Loading a GPTQ quantized model requires the auto-gptq library (`pip install auto-gptq`)"
+            )
+
         gptq_supports_cpu = version.parse(importlib.metadata.version("auto-gptq")) > version.parse("0.4.2")
         if not gptq_supports_cpu and not torch.cuda.is_available():
             raise RuntimeError("GPU is required to quantize or run quantize model.")
-        elif not (is_optimum_available() and is_auto_gptq_available()):
-            raise ImportError(
-                "Loading a GPTQ quantized model requires optimum (`pip install optimum`) and auto-gptq library (`pip install auto-gptq`)"
-            )
         elif version.parse(importlib.metadata.version("auto_gptq")) < version.parse("0.4.2"):
             raise ImportError(
                 "You need a version of auto_gptq >= 0.4.2 to use GPTQ: `pip install --upgrade auto-gptq`"