Update pytest configuration to include "plotpy"

Author: PierreRaybaut

.github/workflows/python-package.yml

@@ -46,4 +46,4 @@ jobs:
         flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
     - name: Test with pytest
       run: |
-        pytest plotpy
+        pytest

pyproject.toml

@@ -82,6 +82,9 @@ include = ["plotpy*"]
 [tool.setuptools.dynamic]
 version = { attr = "plotpy.__version__" }
 
+[tool.pytest.ini_options]
+addopts = "plotpy"
+
 [tool.ruff]
 exclude = [".git", ".vscode", "build", "dist"]
 line-length = 88                               # Same as Black.