Drop win-32 platform CI from appveyor matrix?

[jhamman]

Conda-forge has dropped support for 32-bit windows builds (conda-forge/cftime-feedstock#2 (comment)). Do we want to continue testing against this environment? The point becomes moot after #1876 gets wrapped up in ~7 months.

xref: #1252

[stale]

In order to maintain a list of currently relevant issues, we mark issues as stale after a period of inactivity

If this issue remains relevant, please comment here or remove the stale label; otherwise it will be marked as closed automatically

[keewis]

there's something wrong with the bot, this is not stale but closed

[max-sixty]

Yup, I just reported. It does act up occasionally!

Though it is nice to not have to go through the 550 issue backlog, and mostly rely on it to notify & clean the dead ones...