Computing `expval` and `var` with `LightningTensor` using `quimb` MPS #4653

Job	Run time
C++ tests (ubuntu-22.04, lightning_qubit)	6m 29s
Python tests (ubuntu-22.04, lightning_qubit)	6m 4s
C++ tests (OpenBLAS) (ubuntu-22.04, lightning_qubit)	5m 47s
Python tests with OpenBLAS (ubuntu-22.04, lightning_qubit)	6m 5s
Build and cache Kokkos / Set Kokkos builder matrix	1s
Build and cache Kokkos / Kokkos core (SERIAL)	7s
Build and cache Kokkos / Kokkos core (OPENMP)	3s
C++ tests (multiple backends) (ubuntu-22.04, SERIAL, 4.2.00)	5m 20s
C++ tests (Kokkos) (ubuntu-22.04, lightning_kokkos, SERIAL, 4.2.00)	5m 24s
Python tests with Kokkos (ubuntu-22.04, lightning_kokkos, SERIAL, 4.2.00)	5m 11s
C++ tests (multiple backends) (ubuntu-22.04, OPENMP, 4.2.00)	5m 34s
C++ tests (Kokkos) (ubuntu-22.04, lightning_kokkos, OPENMP, 4.2.00)	5m 9s
Python tests with Kokkos (ubuntu-22.04, lightning_kokkos, OPENMP, 4.2.00)	5m 2s
Python tests with Kokkos (ubuntu-22.04, all, SERIAL, 4.2.00)	5m 3s
Python tests with Kokkos (ubuntu-22.04, all, OPENMP, 4.2.00)	5m 27s
Upload python coverage data to codecov	1s
Upload cpp coverage data to codecov	1s
	1h 6m 48s

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