[BUG] Warnings from cotengra are raised at import of pennylane

[lillian542]

Expected behavior

There is a known minor issue with the cotengra package - it raises some warnings on import for many (all?) environment configurations. It's a requirement for using default.tensor. However, once installed, the warnings are raised when importing PennyLane.

Actual behavior

We should adjust the import locations or catch and re-raise these warnings so that they are raised when initializing default.tensor, instead of any time someone with cotengra in their environment runs import pennylane as qml.

Additional information

100% of the time if cotengra is installed in the environment

Source code

Tracebacks

System information

pl-dev

Existing GitHub issues

• I have searched existing GitHub issues to make sure the issue does not already exist.