chore(deps): update actions/checkout action to v6

.github/workflows/python-app.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Install uv
       uses: astral-sh/setup-uv@v6
       with:

pyproject.toml

@@ -7,7 +7,7 @@ authors = [
 ]
 license= { file = "LICENSE.txt" }
 dependencies = [
-    "pandas[feather,performance]~=3.0.0",
+    "pandas[feather,performance]~=2.3.1",
     "python-stdnum~=2.1",
     "requests~=2.32.3",
     "requests-cache~=1.2.1",