test: fix changelog unit test imports in CI

Author: eddietejeda

tests/test_update_changelog.py

@@ -1,4 +1,15 @@
-from scripts.update_changelog import update_changelog_text
+import importlib.util
+from pathlib import Path
+
+
+def _update_changelog_text(text: str, ver: str, date: str) -> str:
+    path = Path(__file__).resolve().parents[1] / "scripts" / "update_changelog.py"
+    spec = importlib.util.spec_from_file_location("update_changelog", path)
+    module = importlib.util.module_from_spec(spec)
+    assert spec.loader is not None
+    spec.loader.exec_module(module)
+    return module.update_changelog_text(text, ver, date)
+
 
 HEADER = """# Changelog
 
@@ -18,7 +29,7 @@
 
 
 def test_empty_unreleased_inserts_version_without_duplicate_heading():
-    result = update_changelog_text(HEADER, "0.1.2", "2026-05-20")
+    result = _update_changelog_text(HEADER, "0.1.2", "2026-05-20")
     assert result.count("## [Unreleased]") == 1
     assert "## [0.1.2] - 2026-05-20" in result
     assert "The format is based on [Keep a Changelog]" in result.split("## [0.1.2]")[0]
@@ -30,7 +41,7 @@ def test_populated_unreleased_moves_notes_into_new_section():
         "## [Unreleased]\n\n",
         "## [Unreleased]\n\n### Added\n\n- New widget.\n\n",
     )
-    result = update_changelog_text(text, "0.1.2", "2026-05-20")
+    result = _update_changelog_text(text, "0.1.2", "2026-05-20")
     assert result.count("## [Unreleased]") == 1
     assert "- New widget." in result
     assert result.index("- New widget.") < result.index("## [0.1.1]")