diff --git a/.github/workflows/sphinx.yml b/.github/workflows/sphinx.yml
index 5f5a90ce1a2d..3f00094e0264 100644
--- a/.github/workflows/sphinx.yml
+++ b/.github/workflows/sphinx.yml
@@ -41,7 +41,7 @@ jobs:
       - run: uv sync --group=docs
       - uses: actions/configure-pages@v6
       - run: uv run sphinx-build -c docs . docs/_build/html
-      - uses: actions/upload-pages-artifact@v4
+      - uses: actions/upload-pages-artifact@v5
         with:
           path: docs/_build/html
 
diff --git a/sorts/pigeonhole_sort.py b/sorts/pigeonhole_sort.py
index bfa9bb11b8a6..7fbc6188cfb4 100644
--- a/sorts/pigeonhole_sort.py
+++ b/sorts/pigeonhole_sort.py
@@ -10,7 +10,11 @@ def pigeonhole_sort(a):
     >>> pigeonhole_sort(a)  # a destructive sort
     >>> a == b
     True
+
+    >>> pigeonhole_sort([])
     """
+    if not a:
+        return
     # size of range of values in the list (ie, number of pigeonholes we need)
 
     min_val = min(a)  # min() finds the minimum value
@@ -38,7 +42,7 @@ def pigeonhole_sort(a):
 def main():
     a = [8, 3, 2, 7, 4, 6, 8]
     pigeonhole_sort(a)
-    print("Sorted order is:", " ".join(a))
+    print("Sorted order is:", *a)
 
 
 if __name__ == "__main__":
diff --git a/sorts/unknown_sort.py b/sorts/unknown_sort.py
index 9fa9d22fb5e0..3545da68ea80 100644
--- a/sorts/unknown_sort.py
+++ b/sorts/unknown_sort.py
@@ -6,7 +6,7 @@
 """
 
 
-def merge_sort(collection):
+def merge_sort(collection: list) -> list:
     """Pure implementation of the fastest merge sort algorithm in Python
 
     :param collection: some mutable ordered collection with heterogeneous