Move `sudoku_solver` folder to correct location

[Aymeric-e]

Currently, the sudoku_solver folder is nested inside the dice_roll folder. This is not consistent with the intended project structure, as sudoku_solver should be a standalone module at the same level as dice_roll in the repository.

The current structure is:
Python/
└── dice_roll/
└── sudoku_solver/

The expected structure should be:
Python/
├── dice_roll/
├── sudoku_solver/
└── other_folders/

Having sudoku_solver inside dice_roll makes it harder to import the module independently, breaks logical separation of modules, and could confuse contributors or automated tools that rely on a standard repository structure.

It s not much work but moving the sudoku_solver folder out of dice_roll and place it at the root of the project alongside dice_roll would make things nicer and more logical.