Merge pull request labgrid-project#1617 from lemoer/pr_doc_use_importlib

doc: use importlib.metadata in favor of pkg_resources in conf.py

Author: Bastian-Krause

doc/conf.py

@@ -21,7 +21,7 @@
 import sys
 sys.path.insert(0, os.path.abspath('..'))
 
-from pkg_resources import get_distribution
+from importlib.metadata import version
 
 # Import read_the_docs theme
 import sphinx_rtd_theme
@@ -65,7 +65,7 @@
 # built documents.
 #
 # The full version, including alpha/beta/rc tags.
-release = get_distribution('labgrid').version
+release = version('labgrid')
 # The short X.Y version.
 version = '.'.join(release.split('.')[:2])