Update all Prospect accounts that have a Rating of Cold by changing their Type to Other. Return the number of accounts successfully updated. Use Database.update with allOrNone=false to handle partial failures gracefully.

Returns:

• Integer: The number of accounts successfully updated

Requirements:

• Query for Accounts WHERE Type = 'Prospect' AND Rating = 'Cold'
• Update each account Type to 'Other'
• Use Database.update() with allOrNone=false
• Count successful results from SaveResult array

Example:

Integer updated = deactivateOldProspects();
// Returns: 3 (if 3 Cold Prospect accounts were successfully updated)