Fix broken import for python 3.10.12

patches/lib/python3.10/site-packages/sphinx/util/typing.py/patch
----------------------------------------------------------------
  o Imports changed again for python v3.10.12, define Union from typing.
  o Patch fixed broken 'make test' target for local dev use.

Makefile
--------
  o Added venv install dependencies for targets lint and linkcheck.
  o Install dependent patched virtual env for named targets.

Change-Id: Id0681bcd758259efed45d943ea4d316bbd8d4354
diff --git a/Makefile b/Makefile
index 5a307f7..54463fc 100644
--- a/Makefile
+++ b/Makefile
@@ -21,11 +21,7 @@
 ##-------------------##
 ##---]  GLOBALS  [---##
 ##-------------------##
-TOP ?=$(strip \
-  $(dir \
-    $(abspath $(lastword $(MAKEFILE_LIST)))\
-   )\
-)
+TOP ?=$(strip $(dir $(abspath $(lastword $(MAKEFILE_LIST))) ) )
 
 ##--------------------##
 ##---]  INCLUDES  [---##
@@ -70,6 +66,10 @@
 ## -----------------------------------------------------------------------
 test: lint linkcheck
 
+# [TODO] relocate into repo:onf-make/
+lint      : $(venv-activate-patched)
+linkcheck : $(venv-activate-patched)
+
 ## -----------------------------------------------------------------------
 ## Intent: Exercise all generation targets
 ## Bridge: library workaround to support legacy targets