bad optional access when trying to learn a spell from a book that contain spells from mutually exclusive schools of magic

[HadeanLake]

Describe the bug

Game crashes with bad optional access message when player tries to read again from the book that contains spells from mutually exclusive schools of magic if the character already knows spells from one of those schools.
The Home Mage's Healthcare Manual is an example of such book

Attach save file

saved with The Home Mage's Healthcare Manual in inventory
toomanymagics-bad_optional_access-trimmed.tar.gz

Steps to reproduce

1. Learn a spell from The Home Mage's Healthcare Manual
2. Agree to become biomancer or druid and be locked out of the other school
3. Try to read The Home Mage's Healthcare Manual again

Expected behavior

no crash

Screenshots

No response

Versions and configuration

• OS: Linux
  • OS Version: LSB Version: n/a; Distributor ID: Arch; Description: Arch Linux; Release: rolling; Codename: n/a;
• Game Version: cdda-experimental-2024-09-01-1411 746a170 [64-bit]
• Graphics Version: Tiles
• Game Language: System language []
• Mods loaded: [
  Dark Days Ahead [dda],
  Disable NPC Needs [no_npc_food],
  Portal Storms Ignore NPCs [personal_portal_storms],
  Slowdown Fungal Growth [no_fungal_growth],
  Bionic Professions [package_bionic_professions],
  Magiclysm [magiclysm]
  ]

Additional context

No response

[RenechCDDA]

Duplicate of #76110

Thank you for reporting this bug. We already have an issue # tracking this. To keep the reports organized (so we can fix them!) your issue will be closed, and a link provided to keep all conversation together.