Updating default.tensor to the latest quimb version (#6630)

**Context:** With the new version (`1.9.0`) of `quimb`, released on
2024-11-19, `DefaultTensor` no longer works.

This seems to depend on the fact that the `local_expectation` method for
MPS quantum circuits no longer works if `dtype` is specified.

See [this discussion](jcmgray/quimb#268) in
`quimb` for details.

Now that `quimb 1.10` [has been
released](https://quimb.readthedocs.io/en/latest/changelog.html#v1-10-0-2024-12-18),
PennyLane is compatible with `quimb` again.

**Description of the Change:** We just unpin the `quimb` version in the
CI

**Benefits:** `PennyLane` is compatible again with the latest `quimb`,
and we'll know if something is not working.

**Possible Drawbacks:** None.

**Related GitHub Issues:** None.

**Related ShortCut Stories:** [sc-78734]

.github/workflows/interface-unit-tests.yml

@@ -465,7 +465,7 @@ jobs:
       pytest_markers: external
       pytest_additional_args: -W ${{ inputs.python_warning_level }} ${{ inputs.python_warning_level != 'default' && '--continue-on-collection-errors' || '' }}
       additional_pip_packages: |
-        pyzx matplotlib stim quimb==1.8.4 mitiq ply optax scipy-openblas32>=0.3.26
+        pyzx matplotlib stim quimb mitiq ply optax scipy-openblas32>=0.3.26
         git+https://github.com/PennyLaneAI/pennylane-qiskit.git@master
         ${{ needs.default-dependency-versions.outputs.jax-version }}
         ${{ needs.default-dependency-versions.outputs.tensorflow-version }}

doc/releases/changelog-dev.md

@@ -281,6 +281,9 @@ such as `shots`, `rng` and `prng_key`.
 
 <h4>Other Improvements</h4>
 
+* PennyLane is compatible with `quimb 1.10.0`.
+  [(#6630)](https://github.com/PennyLaneAI/pennylane/pull/6630)
+
 * Add developer focused `run` function to `qml.workflow` module.
   [(#6657)](https://github.com/PennyLaneAI/pennylane/pull/6657)