Update sample notebooks that submit jobs to retired H1 hardware

[jlehnersd]

On October 15, 2025, Azure Quantum jobs can no longer be submitted to Quantinuum H1 hardware. Jobs should be submitted to the H2 hardware instead.

The following Jupyter Notebook samples submit jobs to the H1 hardware, so the samples need to be updated:

• https://github.com/microsoft/qsharp/tree/main/samples/chemistry
• https://github.com/microsoft/qsharp/blob/main/samples/notebooks/repeat_until_success.ipynb
• https://github.com/microsoft/qsharp/blob/main/samples/chemistry/Variational%20Quantum%20Algorithms.ipynb