Graphviz error showing up in pytket user guide

https://docs.quantinuum.com/tket/user-guide/manual/manual_circuit.html#implicit-qubit-permutations

<img width="760" alt="Image" src="https://github.com/user-attachments/assets/51059ec3-e299-4afe-a42b-6fa23038d5ad" />

Likely due to pytket being installed improperly in the new central build with the graphviz executable not being installed.