tox.ini: remove old workaround in schemacheck env

It's been more than a few weeks.

Signed-off-by: John Mulligan <[email protected]>

tox.ini

@@ -66,14 +66,6 @@ deps =
     PyYAML
 commands =
     python -m sambacc.schema.tool
-# The following env var is a workaround for running this testenv on fedora 39
-# with python 3.12.1. As of approx. 2023-12-11 the ci started # to fail because
-# of the multidict library (not even one of our direct dependencies) failing
-# to install from source because we (intentionally) have no C compiler in the
-# image. Try to remove this in a few weeks to see if wheel availability or
-# whatever has been resolved.
-setenv =
-    MULTIDICT_NO_EXTENSIONS=1
 
 [testenv:schemaupdate]
 description = Regenerate source files from JSON Schema file(s)