Resolve MaxNLocator IndexError when no large steps

[ddeibert-nso]

PR summary

Resolves IndexError in MaxNLocator._raw_ticks().

The IndexError occurred under the following conditions:

• nbins=1
• rcParams['axes.autolimit_mode'] == 'round_numbers'
• the input parameters for vmin and vmax resulted in no large_steps (all are False)

closes #27603

PR checklist

• "closes #0000" is in the body of the PR description to link the related issue
• new and changed code is tested
• [N/A] Plotting related features are demonstrated in an example
• [N/A] New Features and API Changes are noted with a directive and release note
• [N/A] Documentation complies with general and docstring guidelines

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[ddeibert-nso]

I think a second approval is required before this PR can be merged. I don't think anything is needed from me to proceed. If there is, please let me know.

[tacaswell]

Thank you for your work @ddeibert-nso and congratulations 🎉 on your first merged PR to Matplotlib.

I hope we hear from you again!