Fix version in docs

docs/source/conf.py

@@ -10,12 +10,11 @@
 # serve to show the default.
 
 import contextlib
+import importlib.metadata
 import os
 import sys
 import time
 
-import aiida_test_cache
-
 # -- AiiDA-related setup --------------------------------------------------
 
 # If extensions (or modules to document with autodoc) are in another directory,
@@ -76,7 +75,7 @@
 # built documents.
 #
 # The full version, including alpha/beta/rc tags.
-release = aiida_test_cache.__version__
+release = importlib.metadata.version('aiida_test_cache')
 # The short X.Y version.
 version = '.'.join(release.split('.')[:2])