ENH: use importlib to collect hg resources

- importlib only available since python 3.9
- turn off tests for deprecated python 3.8

Author: kx79wq

.github/workflows/test.yml

@@ -10,7 +10,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        python: ['3.8', '3.9', '3.10', '3.11', '3.12']
+        python: ['3.9', '3.10', '3.11', '3.12']
     runs-on: ${{ matrix.os }}
 
     steps:

histogrammar/notebooks/__init__.py

@@ -19,22 +19,19 @@
 
 
 # Resources lookup file for histogrammar
-
-import pathlib
-
-ROOT_DIRECTORY = pathlib.Path(__file__).resolve().parent
+from importlib import resources
 
 
 # data files that are shipped with histogrammar.
 _DATA = {
     _.name: _
-    for _ in pathlib.Path(ROOT_DIRECTORY / "test_data").glob("*")
+    for _ in resources.files("histogrammar.test_data").iterdir()
 }
 
 # Tutorial notebooks
 _NOTEBOOK = {
-    _.name: _
-    for _ in pathlib.Path(ROOT_DIRECTORY / "notebooks").glob("*.ipynb")
+    p.name: p
+    for p in resources.files("histogrammar.notebooks").iterdir() if p.suffix == ".ipynb"
 }
 
 # Resource types