Submitted by D1r3Wolf, also found by 0x_kmr_ and Spearmint
https://github.com/code-423n4/2025-01-pump-science/blob/768ef58478724bf6b464c9f0952e3e5a3b2a2613/programs/pump-science/src/state/global.rs#L119-L132
https://github.com/code-423n4/2025-01-pump-science/blob/768ef58478724bf6b464c9f0952e3e5a3b2a2613/programs/pump-science/src/state/global.rs#L66
During the audit, it was identified that the migration_token_allocation variable on the Global struct is not updated in the Global::update_settings function. This creates a critical issue as the migration_token_allocation value, which is used during the migration process in the create_pool instruction, will remain uninitialized or stuck at its default value indefinitely.  
The update_settings function is executed within the set_params instruction, making it a central mechanism for modifying key global settings. However, due to the missing update logic for migration_token_allocation, any updates intended for this variable via GlobalSettingsInput are ignored. As a result, the migration_token_allocation on the Global struct is never updated, leading to a persistent and incorrect value that could disrupt the migration process.
Notes: Execute the test case in src/state/bonding_curve/tests.rs
Impact: 
The migration_token_allocation will retain its default value indefinitely, regardless of any intended updates.
To resolve this issue, we recommend the following steps:  
Kulture (Pump Science) confirmed
