feat: remove pkg_resource

- replace pkg_resource with importlib
- ensure python 3.8 support is removed
- ensure xblock >= 5.0.0
- ensure tests success

done/__init__.py

@@ -4,4 +4,4 @@
 
 from .done import DoneXBlock
 
-__version__ = '2.3.0'
+__version__ = '2.4.0'

done/done.py

@@ -5,7 +5,7 @@
 
 import uuid
 
-import pkg_resources
+import importlib.resources
 from web_fragments.fragment import Fragment
 from xblock.core import XBlock
 from xblock.fields import Boolean, DateTime, Float, Scope, String
@@ -26,8 +26,8 @@ def _(text):
 
 def resource_string(path):
     """Handy helper for getting resources from our kit."""
-    data = pkg_resources.resource_string(__name__, path)
-    return data.decode("utf8")
+    data = importlib.resources.files(__package__).joinpath(path)
+    return data.read_text(encoding="utf8")
 
 
 @XBlock.needs('i18n')