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`

.github/workflows/test.yml

@@ -53,7 +53,14 @@ jobs:
           poetry install --all-extras
 
       - name: Test with pytest
-        run: pytest -v --cov=./lerobot --durations=0 tests
+        run: |
+          pytest tests -v --cov=./lerobot --durations=0 \
+            -W ignore::DeprecationWarning:imageio_ffmpeg._utils:7 \
+            -W ignore::UserWarning:torch.utils.data.dataloader:558 \
+            -W ignore::UserWarning:gymnasium.utils.env_checker:247 \
+            && rm -rf tests/outputs outputs
 
       - name: Test end-to-end
-        run: make test-end-to-end
+        run: |
+          make test-end-to-end \
+            && rm -rf outputs