Add a test for Versions.filter with default branch

Author: hugovk

tests/test_build_docs_versions.py

@@ -3,17 +3,17 @@
 
 def test_filter_default() -> None:
     # Arrange
-    versions = [
+    versions = Versions([
         Version("3.14", status="feature"),
         Version("3.13", status="bugfix"),
         Version("3.12", status="bugfix"),
         Version("3.11", status="security"),
         Version("3.10", status="security"),
         Version("3.9", status="security"),
-    ]
+    ])
 
     # Act
-    filtered = Version.filter(versions)
+    filtered = versions.filter()
 
     # Assert
     assert filtered == [