fixup! chore(legacy): remove CoSi functionality

legacy/firmware/layout2.c

@@ -1339,14 +1339,6 @@ void layoutNEMLevy(const NEMMosaicDefinition *definition, uint8_t network) {
 
 #endif
 
-static inline bool is_slip18(const uint32_t *address_n,
-                             size_t address_n_count) {
-  // m / 10018' / [0-9]'
-  return address_n_count == 2 && address_n[0] == (PATH_HARDENED + 10018) &&
-         (address_n[1] & PATH_HARDENED) &&
-         (address_n[1] & PATH_UNHARDEN_MASK) <= 9;
-}
-
 void layoutConfirmAutoLockDelay(uint32_t delay_ms) {
   char line[sizeof("after 4294967296 minutes?")] = {0};