do not pass env argument into deprecated builders

Changes to the builder to move towards passing an environment into the
builder [1] can cause some legacy builder types to fail to load [2].
For example:

    Traceback (most recent call last):
      File "/home/runner/work/confluencebuilder/confluencebuilder/.tox/py38-sphinx51/lib/python3.8/site-packages/sphinx/registry.py", line 162, in create_builder
        return self.builders[name](app, env)
    TypeError: __init__() takes 2 positional arguments but 3 were given

The fallback case for preparing deprecated builders should avoid setting
`env`.

[1]: 6ef22d2
[2]: sphinx-contrib/confluencebuilder#691

Signed-off-by: James Knight <james.d.knight@live.com>

sphinx/registry.py

@@ -166,7 +166,7 @@ def create_builder(self, app: "Sphinx", name: str,
                 f"'env'argument. Report this bug to the developers of your custom builder, "
                 f"this is likely not a issue with Sphinx. The 'env' argument will be required "
                 f"from Sphinx 7.", RemovedInSphinx70Warning, stacklevel=2)
-            builder = self.builders[name](app, env=...)  # type: ignore[arg-type]
+            builder = self.builders[name](app)
             if env is not None:
                 builder.set_environment(env)
             return builder