Revert Python version in github worflows

Author: danniel

.github/workflows/backend_check.yml

@@ -37,7 +37,7 @@ jobs:
         uses: astral-sh/setup-uv@v7
         with:
           working-directory: ./backend
-          python-version: "3.14"
+          python-version: "3.13"
           cache-dependency-glob: |
             **/pyproject.toml
             **/uv.lock
@@ -70,7 +70,7 @@ jobs:
         uses: astral-sh/setup-uv@v7
         with:
           working-directory: ./backend
-          python-version: "3.14"
+          python-version: "3.13"
           cache-dependency-glob: |
             **/pyproject.toml
             **/uv.lock

docker/dockerfiles/Dockerfile

@@ -1,4 +1,6 @@
 ARG NODE_VERSION=24.14.1
+# Python 3.14 introduced a new GC which has some memory issues:
+# https://discuss.python.org/t/reverting-the-incremental-gc-in-python-3-14-and-3-15/107014
 ARG PYTHON_VERSION=3.13.13
 ARG S6_OVERLAY_VERSION=3.2.2.0