ci: update github actions workflows (#2476)

Author: afuetterer

.github/workflows/testing.yml

@@ -12,9 +12,9 @@ on:
 
 jobs:
   lint:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: actions/setup-python@v6
       with:
         python-version: "3.13"
@@ -28,7 +28,7 @@ jobs:
         python-version: ["3.10", "3.11", "3.12", "3.13"]
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Install latest version of uv and set up Python ${{ matrix.python-version }}
       uses: astral-sh/setup-uv@v7
       with: