Timeout for auto prover

[etiennecallies]

You can view the loader on preprod:

• with success https://linearon.modusponens.dev/?s=%3F%3F%3F%3F%3F1%2C%21%21%21%21%21_*1
• with fail https://linearon.modusponens.dev/?s=%3FA%2C+%3F%28B%E2%85%8BB%29%2C+%3F%28A%5E%E2%85%8BB%5E%29%2C+%3F%28%E2%8A%A5%E2%8A%97%E2%8A%A5%29

The max execution time has been arbitrary set to 3 seconds. There is no more exponential bound, but the prover tries with a bound of 2,3,4, ... until timeout.

Thus new sequents are provable, among them the famous ?((A+A^)*(((B*B)+B^)|((B*B)+B^)))