Don't kick player back to an earlier scene when they run out of lives

[wjt]

Currently, when the player runs out of lives, they are kicked back to the start of the current challenge. “Current challenge” is defined to be:

• If 1 or more threads have been collected on this quest: the scene the last thread they collected took them to
• Otherwise: the first scene of the quest

For example:

1. If they are defeated by the void 3 times in res://scenes/quests/lore_quests/quest_002/3_void_grappling/void_grappling_round_2.tscn, they are returned to the start of res://scenes/quests/lore_quests/quest_002/3_void_grappling/void_grappling.tscn
2. If they are caught by a guard three times in the stealth challenge in NO_EDIT, they are taken back to... the opening cutscene
3. Similarly, if they are caught by the terrifying monster three times in the stealth challenge at the start of Sueños Nocturnos, they are taken back to the opening cutscene. (There are two cutscenes.)

2 and 3 are the result of a simplistic definition of "start of challenge".

By contrast, 1 is intentional behaviour. But playtesting feedback such as in #1944, and my own personal experience from testing the game, is that it's incredibly frustrating to be kicked back several levels. I think we need to change this.

[wjt]

I can see two options:

Option 1

When the player runs out of lives, kick them back to the start of the current scene rather than the current challenge. This would mean:

• No change for the Musician quest's stealth challenge, since it is a single scene
• Being caught 3 times by the Mothsache in res://scenes/quests/lore_quests/quest_003/2_ink_drinker_levels/ink_combat_round_6.tscn would just restart that level, as if you had lost a single life
• Same for being caught 3 times in void_grappling_round_2
• And it would fix problems 2 and 3 above

This kind of takes the teeth out of running out of lives in most levels.

Option 2

Just remove lives entirely.