ensure_backup_directory has a hard-coded path

[Gilrain]

The ensure_backup_directory function in backup_routes.py tries to create a "data" folder using the installation path.

On a read only file system this results in a failed launch.

Creating a softlinked "data" folder under ~/.config/huntarr/ allows the program to start.

huntarr 8.2.10-1 on Arch Linux

Log:

OSError: [Errno 30] Read-only file system: '/usr/share/webapps/huntarr/data'
    ~~~~~~~~^^^^^^^^^^^^
    os.mkdir(self, mode)
  File "/usr/lib/python3.13/pathlib/_local.py", line 722, in mkdir
    ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    self.parent.mkdir(parents=True, exist_ok=True)
  File "/usr/lib/python3.13/pathlib/_local.py", line 726, in mkdir
    ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    self.backup_dir.mkdir(parents=True, exist_ok=True)
  File "/usr/share/webapps/huntarr/src/routes/backup_routes.py", line 128, in ensure_backup_directory
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
    self.ensure_backup_directory()
  File "/usr/share/webapps/huntarr/src/routes/backup_routes.py", line 104, in __init__
    backup_manager = BackupManager()
  File "/usr/share/webapps/huntarr/src/routes/backup_routes.py", line 445, in <module>
    from src.routes.backup_routes import backup_bp
  File "/usr/share/webapps/huntarr/src/primary/web_server.py", line 54, in <module>
    from primary.web_server import app
  File "/usr/share/webapps/huntarr/main.py", line 108, in <module>
Traceback (most recent call last):
During handling of the above exception, another exception occurred:
FileNotFoundError: [Errno 2] No such file or directory: '/usr/share/webapps/huntarr/data/backups'
    ~~~~~~~~^^^^^^^^^^^^
    os.mkdir(self, mode)
  File "/usr/lib/python3.13/pathlib/_local.py", line 722, in mkdir
Traceback (most recent call last):
CRITICAL:HuntarrRoot:Fatal Error: An unexpected error occurred during initial imports: [Errno 30] Read-only file system: '/usr/share/webapps/huntarr/data'
ERROR:src.routes.backup_routes:Failed to create backup directory: [Errno 30] Read-only file system: '/usr/share/webapps/huntarr/data'