bump tensorflow to 2.15 in CI

[timmysilv]

For some reason in 2.15, the ndim() of an abstract tensor with shape specified as None was -1, so it didn't raise an error, and didn't get handled with this exception handling

Description of the change
qml.math.ndim(tensor) always returns len(tensor.shape) for tensorflow. this will still raise errors as expected for abstract tensors with abstract shapes (only happens when the user specifies the shape as None before compiling a function).

ran a bunch of tests (tf interface tests, the tf.function test that failed in test_operation.py) locally with python 3.9, TF 2.10 just to make sure I didn't break old versions of tensorflow, they all passed 🙌

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (bce513e) 99.65% compared to head (d28de6c) 99.66%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4847   +/-   ##
=======================================
  Coverage   99.65%   99.66%           
=======================================
  Files         382      382           
  Lines       34507    34501    -6     
=======================================
- Hits        34389    34384    -5     
+ Misses        118      117    -1     

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[albi3ro]

Great job finding this :) does it still work on older tf versions?

[timmysilv]

I did:

pip install tensorflow-macos==2.10
pytest tests/interfaces/default_qubit_2_integration/test_tensorflow_qnode_default_qubit_2.py \
    tests/test_operation.py::TestBroadcasting::test_with_tf_function

with python 3.9, and it passed