Remove warnings (#111)

- Replace `use_pretrained_backbone` with `pretrained_backbone_weights`
- Bump diffusers' minimum version `0.26.3` -> `0.27.2`
- Add ignore flags in CI's pytest
- Change Box observation spaces in simulation environments
- Set `version_base="1.2"` in Hydra initializations
- Bump einops' minimum version `0.7.0` -> `0.8.0`

lerobot/common/policies/act/modeling_act.py

@@ -104,7 +104,7 @@ class ActionChunkingTransformerPolicy(nn.Module):
         # Backbone for image feature extraction.
         backbone_model = getattr(torchvision.models, cfg.vision_backbone)(
             replace_stride_with_dilation=[False, False, cfg.replace_final_stride_with_dilation],
-            pretrained=cfg.use_pretrained_backbone,
+            weights=cfg.pretrained_backbone_weights,
             norm_layer=FrozenBatchNorm2d,
         )
         # Note: The assumption here is that we are using a ResNet model (and hence layer4 is the final feature