👷(docker) add arm64 support and upgrade CI workflow steps (#11)

* 👷(docker) add arm64 platform support for image builds

Add QEMU and Buildx setup steps to enable multi-architecture Docker
image builds for both linux/amd64 and linux/arm64 platforms.

Signed-off-by: Stephan Meijer <me@stephanmeijer.com>

* ⬆️(ci) upgrade GitHub Actions workflow steps to latest versions

Update actions/setup-node from v4 to v6 and actions/cache from v4 to v5
for improved performance, security patches, and Node.js runtime compatibility.

Signed-off-by: Stephan Meijer <me@stephanmeijer.com>

---------

Signed-off-by: Stephan Meijer <me@stephanmeijer.com>

.github/workflows/crowdin_upload.yml

@@ -40,7 +40,7 @@ jobs:
           DJANGO_CONFIGURATION=Build python manage.py makemessages -a --keep-pot
       # frontend i18n
       - name: Restore the frontend cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: "src/frontend/**/node_modules"
           key: front-node_modules-${{ hashFiles('src/frontend/**/yarn.lock') }}