Revert changes to use onf-make

onf-make was never compatible with this repo. For now, we want to
revert these changes so that the build can work properly again.

Signed-off-by: Eric Ball <eball@linuxfoundation.org>
Change-Id: I0afb08030edcae4d2e968c63ef5eb11e17085d8a
diff --git a/conf.py b/conf.py
index 13415f7..009f01c 100644
--- a/conf.py
+++ b/conf.py
@@ -60,7 +60,7 @@
 
 project = "VOLTHA Docs"
 copyright = (
-    "Copyright 2019-2024 Open Networking Foundation Contributors"
+    "Copyright 2019-2025 Open Networking Foundation Contributors"
 )
 author = "VOLTHA Contributors"
 
@@ -147,7 +147,7 @@
 #
 # This is also used if you do content translation via gettext catalogs.
 # Usually you set "language" from the command line for these cases.
-language = None
+language = "en"
 
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = None