Install script should overwrite existing symlinks in gtk-4.0 directory

[OlaoluwaM]

Is there an existing issue outlining your problem?

• [X] I have searched the existing issues and they do not solve my problem.

Describe the bug.

Right now the script fails if symlinks already exist in the gtk-4.0 directory when you pass the --link flag to the script

[catppuccin-gtk] [INFO] - Installation info:
        flavor:     mocha
        accent:     lavender
        dest:       /home/olaolu/.local/share/themes
        link:       True
remote_url: https://github.com/catppuccin/gtk/releases/download/v1.0.2/catppuccin-mocha-lavender-standard+default.zip
[catppuccin-gtk] [INFO] - Starting download...
[catppuccin-gtk] [INFO] - Response status: 200
[catppuccin-gtk] [INFO] - Download finished, zip is valid
[catppuccin-gtk] [INFO] - Verifying download..
[catppuccin-gtk] [INFO] - Download verified
[catppuccin-gtk] [INFO] - Extracting...
[catppuccin-gtk] [INFO] - Extraction complete
[catppuccin-gtk] [INFO] - Adding symlinks for libadwaita
[catppuccin-gtk] [INFO] - Root:   /home/olaolu/.local/share/themes/catppuccin-mocha-lavender-standard+default-dark/gtk-4.0
[catppuccin-gtk] [INFO] - Target: /home/olaolu/.config/gtk-4.0
[catppuccin-gtk] [ERROR] - Something went wrong when installing the theme:
Traceback (most recent call last):
  File "/home/olaolu/install.py", line 214, in <module>
    main()
  File "/home/olaolu/install.py", line 209, in main
    install(ctx)
  File "/home/olaolu/install.py", line 161, in install
    add_libadwaita_links(ctx)
  File "/home/olaolu/install.py", line 143, in add_libadwaita_links
    os.symlink(dir_name / "assets", gtk4_dir / "assets")
FileExistsError: [Errno 17] File exists: '/home/olaolu/.local/share/themes/catppuccin-mocha-lavender-standard+default-dark/gtk-4.0/assets' -> '/home/olaolu/.config/gtk-4.0/assets'

Attach screenshots.

No response

How did you install the theme?

From release (install.py)

Are you running the latest release, and if not does the issue persist there?

• [X] I am running on the latest release & the issue persists there

If using GTK4, have you symlinked the "gtk-4.0" folder?

• [ ] I have symlinked the gtk-4.0 folder.

What GNOME version are you seeing the bug on?

GNOME Shell 46.2

Any additional comments?

No response

[nullishamy]

Tracking in #257