Implement checkpoint system for asteroid network

[Ranjana-git7]

@aadit-n3rdy

Fixed menu freezing by moving rendering code outside the event loop.

Changed asteroids-group to asteroids_group to fix a syntax error.

Added import asteroid to resolve reference errors.

Fixed UI button responsiveness in the Game Over menu.

[Devpool-soc]

Hey @Ranjana-git7! Thank you for opening a pull request. Make sure to tag the maintainers and link the issue you are solving in your pull-request description if you have not already and they'll review as soon as possible.

[aadit-n3rdy]

@Ranjana-git7 please use the checkpointing system to generate weights as well, so that when the game is run in "standard mode" it automatically uses these weights

Edit: the weights must be in the PR, so that when the user runs the game in standard mode even for the first time, it works perfectly

[Ranjana-git7]

@aadit-n3rdy
Thank you for the review and suggestion.

This PR implements a checkpointing system for the asteroid neural network so that standard gameplay works smoothly even on the first run.

Changes
Added save and load functionality to the neural network class
Automatically checkpoints the best-performing asteroid network during gameplay
Loads pretrained weights (if available) when spawning new asteroids
Ensured stable game loop behavior during asteroid respawn and evolution
Verification
The game runs correctly in standard mode
The checkpoint file (weights.pkl) is generated automatically during gameplay
The saved weights are reused as expected

[aadit-n3rdy]

@Ranjana-git7 please resolve the merge conflicts