Incorrect unlock info in Story Mode

[Alayan-stk-2]

Seen with 1.4 :

• Going from 88 to 98 points, displayed "Candela City" and "Around the Lighthouse" as unlocked.
• Going from 98 to 128 points, displayed "Candela City" and "Around the Lighthouse" (again) as unlocked. The tracks that were actually unlocked were Minigolf and Northern Resort

[Alayan-stk-2]

Testing confirms https://github.com/supertuxkart/stk-code/pull/4980 fixes this

[Alayan-stk-2]

Duplicate of https://github.com/supertuxkart/stk-code/issues/4254