Update python Docker tag to v3.13.0b4

Prevent renovate from picking up updates until they're 7 days old

Reviewed-on: #15

Dockerfile

@@ -1,4 +1,4 @@
-FROM python:3.13.0a6-alpine3.19
+FROM python:3.13.0b4-alpine3.19
 
 RUN apk add curl
 

renovate.json

@@ -1,7 +1,7 @@
-
 {
     "extends": [":automergeMinor", ":automergePr", ":automergeRequireAllStatusChecks", ":dependencyDashboard", ":disableRateLimiting", ":rebaseStalePrs"],
     "major": {
       "dependencyDashboardApproval": true
-    }
+    },
+    "minimumReleaseAge": "7 days"
 }