Tweak requirements.txt so I can actually install from it

I'm setting up a virtual environment for the first time, and, trying
to install my dependencies, I ran into errors, 1. because of appscript
which is only intended for Mac, 2. PyGObject which IS for Linux, but
fails to install, missing "libgirepository1.0-dev", but it's optional,
it's just for wallpaper support. pyxgd is also for wallpaper support,
so maybe I should comment it out too.
And finally, [dev] is needed in order to use the `textual` command.

I don't know how well this can install on other systems, but at least
I can install it now, on Ubuntu.

Also, when the version numbers in my requirements.txt were bumped
when regenerating it, I'm guessing now that the dependencies weren't
actually upgraded, since `textual --version` gave me "0.19.1" up until
I set up my virtual environment (.venv), and now it matches the
requirements.txt version of "0.22.3". I still don't know why the version
numbers were bumped, or for sure that they weren't installed at those
versions somewhere in my filesystem. (I hope virtualenv makes things
more comprehensible, rather than more confusing...)

Also, now that I'm using textual 0.22.3, the radio button set has
arrow key navigation. Seeing this feature missing was what prompted me
to set up the virtual environment and (sort of implicitly) upgrade.
However, it doesn't work correctly, for the flipped horiz./vert. layout.

requirements.txt

@@ -1,9 +1,9 @@
-appscript==1.2.2
+appscript==1.2.2; sys_platform == 'darwin'
 psutil==5.9.0
-PyGObject==3.42.1
+# PyGObject==3.42.1
 pyperclip==1.8.2
 pyxdg==0.28
 rich==13.3.5
 stransi==0.3.0
-textual==0.22.3
+textual[dev]==0.22.3
 watchdog==3.0.0