test_buffers.py::test_device was not actually checking the device of tensors

[rhaps0dy]

Description

I added a failure in case of unknown type to test_buffers.py::test_device, and made it iterate correctly through Tensors and dicts.

Motivation and Context

In test_buffers.py::test_device, the assertions that the device be the correct one would not be executed for RolloutBuffer and DictRolloutBuffer: the type of value is RolloutBufferSamples and DictRolloutBufferSamples respectively and so falls to the else case.

I have not raised an issue on purpose, why bother for a tiny bugfix.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (update in the documentation)

Checklist:

• I've read the CONTRIBUTION guide (required)
• I have updated the changelog accordingly (required).
• My change requires a change to the documentation.
• I have updated the tests accordingly (required for a bug fix or a new feature).
• I have updated the documentation accordingly.
• I have reformatted the code using make format (required)
• I have checked the codestyle using make check-codestyle and make lint (required)
• I have ensured make pytest and make type both pass. (required)
• I have checked that the documentation builds using make doc (required)

Note: You can run most of the checks using make commit-checks.

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[qgallouedec]

Use TypeError instead

[araffin]

I could not edit this PR, so I'll push the updated version in a new PR