a path to making Pixi the default `conda_install_tool`

[lucascolley]

A suggestion:

• Make Pixi faster to provision the base env than micromamba on win-64
• Use Pixi on staged-recipes use conda_install_tool: pixi in staged-recipes? staged-recipes#32875 MNT: use Pixi to provision base env in CI staged-recipes#33007
• Check that everything is working
• Flip the switch in smithy

[baszalmstra]

Make Pixi faster to provision the base env than micromamba on win-64

This has been tackled right?