build: change the fallback version suffix to `+git.{sha}`

Seems to be more commonly used than the current `-commit-{sha}`.
Also cleanup/simplify the version handling code and fix the list
of dependencies in the CI scripts.

Change-Id: I75d9e492523c296ad69c5b94be071836308f4ad8
diff --git a/docs/conf.py b/docs/conf.py
index a2f3622..9f303e3 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -10,7 +10,7 @@
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#project-information
 
 project = 'NAC: Name-based Access Control library'
-copyright = 'Copyright © 2014-2023 Regents of the University of California.'
+copyright = 'Copyright © 2014-2024 Regents of the University of California.'
 author = 'Named Data Networking Project'
 
 # The short X.Y version.