v3.7-ls263

CI Report:

https://ci-tests.linuxserver.io/linuxserver/healthchecks/v3.7-ls263/index.html

LinuxServer Changes:

Enable IPv6 on uwsgi.

healthchecks Changes:

Improvements

• Increase outgoing webhook timeout from 10 to 30 seconds
• Remove pruneflips management command (now cleaned up automatically)
• Remove prunenotifications management command (now cleaned up automatically)
• Update settings.py to read SECURE_PROXY_SSL_HEADER from env vars
• Remove LINE Notify onboarding form (as LINE Notify is shutting down on Apr 1, 2025)
• Make slider labels clickable in the "Update Period & Grace" dialog (#1039)
• Update the Signal integration to retry on network errors

Bug Fixes

• Update sqlite settings to avoid "Database is locked" errors (#1057)
• Fix API to gracefully handle too long slugs