REL: v3.6.1

This is the first bugfix release of the 3.6.x series.

This release contains several bug-fixes and adjustments:

* A warning is no longer raised when constrained layout explicitly
  disabled and tight layout is applied
* Add missing `get_cmap` method to `ColormapRegistry`
* Adding a colorbar on a `ScalarMappable` that is not attached to an
  `Axes` is now deprecated instead of raising a hard error
* Fix `barplot` being empty when first element is NaN
* Fix `FigureManager.resize` on GTK4
* Fix `fill_between` compatibility with NumPy 1.24 development version
* Fix `hexbin` with empty arrays and log scaling
* Fix `resize_event` deprecation warnings when creating figure on macOS
* Fix build in mingw
* Fix compatibility with PyCharm's interagg backend
* Fix crash on empty `Text` in PostScript backend
* Fix generic font families in SVG exports
* Fix horizontal colorbars with hatches
* Fix misplaced mathtext using `eqnarray`
* `stackplot` no longer changes the Axes cycler