Confusing X-axis on nightly runs plot

Example: https://spacetelescope.github.io/bench/astropy-benchmarks/#units.TimeQuantityOpSmallArrayDiffUnit.time_quantity_mul

I expected v7.1.dev to appear after all the v6.x. @zacharyburnett , do you know what is happening here? Thanks!

Open the benchmark page at the linked example and inspect how the nightly-run plot orders version labels on its x-axis. Trace the plotting entry point and determine why v7.1.dev is not placed after the v6.x series; done means the displayed versions follow the expected chronological order.

Written by the indexing model from the issue text.