chore: improve renovate dependency detection

Dockerfile

@@ -1,12 +1,12 @@
 # syntax=docker.io/docker/dockerfile:1
 
-FROM "python:3.11-alpine" AS pipdependencies
+FROM python:3.11-alpine AS pipdependencies
 
 COPY app/requirements.txt /requirements.txt
 
 RUN pip3 install --no-cache-dir --user --requirement requirements.txt
 
-FROM "python:3.11-alpine"
+FROM python:3.11-alpine
 LABEL maintainer="Cabillot Julien <dockerimages@cabillot.eu>"
 
 # TODO: à tester

renovate.json

@@ -0,0 +1,14 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "regexManagers": [
+    {
+      "description": "Track ntfy binary in COPY --from",
+      "fileMatch": ["^Dockerfile$"],
+      "matchStrings": [
+        "COPY --from=binwiederhier/ntfy:(?<currentValue>[^\\s]+)"
+      ],
+      "depNameTemplate": "binwiederhier/ntfy",
+      "datasourceTemplate": "docker"
+    }
+  ]
+}