Tunarr: fix path to backup during update

[SystemIdleProcess]

✍️ Description

1. Started to receive oom-kill messages related to Tunarr container when it was doing library scans at night. Test increasing 1 GB at a time until it was stable. Also, disk space was running very low so increased to a more reasonable size.
2. The location check in order to backups is not the location that Tunarr stores it's data files. Updated the path so backups work properly during updates.

🔗 Related Issue

Fixes #

✅ Prerequisites (X in brackets)

• Self-review completed – Code follows project standards.
• Tested thoroughly – Changes work as expected.
• No security risks – No hardcoded secrets, unnecessary privilege escalations, or permission issues.

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🛠️ Type of Change (X in brackets)

• 🐞 Bug fix – Resolves an issue without breaking functionality.
• ✨ New feature – Adds new, non-breaking functionality.
• 💥 Breaking change – Alters existing functionality in a way that may require updates.
• 🆕 New script – A fully functional and tested script or script set.
• 🌍 Website update – Changes to script metadata (PocketBase/website data).
• 🔧 Refactoring / Code Cleanup – Improves readability or maintainability without changing functionality.
• 📝 Documentation update – Changes to README, AppName.md, CONTRIBUTING.md, or other docs.

[SystemIdleProcess]

A note on the RAM increase. If this is not acceptable to increase it by that much then we can set an environment variable to limit how much is used during scan.
https://tunarr.com/getting-started/run/#search-meilisearch
TUNARR_SEARCH_REDUCE_INDEXER_MEMORY_USAGE

[michelroegl-brunner]

The 4b ram is a bit much. how big is your libary? No such issue has surfaced until now, so maybe its just a "you" problem, wich dose not really warrant quadripeling the defaults.

[SystemIdleProcess]

Reverted resource updates so only fix is backup.

[tremor021]

LGTM on the backup issue. Resources we don't really touch unless really necessarry for everyone or for the app to function. You obviously need to match allocated resources to the application workload, thats on the user