Update actions/checkout action to v6

.github/workflows/python-app.yml

@@ -34,7 +34,7 @@ jobs:
     runs-on: ubuntu-24.04
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0  # Shallow clones should be disabled for a better relevancy of analysis
     - name: Set up Python 3.13

ha_addons/ha_addon/Dockerfile

@@ -13,7 +13,7 @@
 # 1 Build Base Image #
 ######################
 
-ARG BUILD_FROM="ghcr.io/hassio-addons/base:19.0.0"
+ARG BUILD_FROM="ghcr.io/hassio-addons/base:18.1.4"
 # hadolint ignore=DL3006
 FROM $BUILD_FROM AS base