[orca-list] Do not use AT-SPI 2.9.3

[Mike Gorse <mgorse alum wpi edu>]

Hi all,

AT-SPI 2.9.3 has a bug that will cause deadlock / long freezes when trying 
to navigate the Orca preferences dialog. The issue was previously hacked 
around by having at-spi2-atk behave differently when AT_SPI_CLIENT is set 
(ie, in pyatspi), but this hack was removed in 2.9.3 while fixing a freeze 
that could show up in gnome-shell.

The issue is fixed properly in git, and at-spi2-core and at-spi2-atk 2.9.4 
will be released next Monday.

If anyone is using 2.9.x, then I'd suggest either sticking with 2.9.2 for 
the next week or pulling from git (you'd need to update both at-spi2-core 
and at-spi2-atk).

Sorry for the trouble.

-Mike