Fixes black raptors not hatching from eggs with 6+ color inheritance. (#94513)

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## About The Pull Request

Fixes issue #94484 , where black raptors don't spawn from eggs with 6 or
more inherited colors.
The fix is done by changing a check against "==
length(GLOB.raptor_colors))" to ">= (length(GLOB.raptor_colors) - 1))".
Let me know if I should go back to the drawing board, here.

Benefits of this approach:
- Fixes the base issue; if red, green, purple, yellow, white, and blue
raptors are cross-bred, black raptors can be guaranteed.
- Offspring of black raptors will now also be guaranteed black raptor
spawns.

Drawbacks and risks of this approach:
- Doesn't do much for extensibility if more rare raptor colors are to be
added.
- May make black raptors too accessible, especially since one black
raptor means all future breeding attempts will also result in a black
raptor.
- Introduces an issue in which a black raptor can be guaranteed from 5
non-rares and 1 black raptor. I figured this wouldn't be considered a
problem from the player perspective.
- I'm not a professional coder, so I may have missed some obvious
issues.


## Why It's Good For The Game

If I interpret the description in PR #93564 correctly, black raptors
were originally intended to hatch from eggs that had all six raptor
colors besides black. (The exception: If there was a color combination
that guaranteed a specific resulting color, the guaranteed color would
still take precedence.)

This allows Black Raptors to be an achievable goal beyond breeding as
many raptors as possible and hoping for the 1/199 chance to hit.


## Proof of Testing

<img width="439" height="133" alt="RaptorFix"
src="https://github.com/user-attachments/assets/79507355-34ec-4a97-b586-37653229a2d8"
/>

Verified:
- Non-guaranteed combos result in a black raptor if the inheritance list
is 6 or higher
- Includes the offspring of black raptors hatched in this way
- Same-color pairs, even with 6+ inheritance colors, will result in a
hatchling of the same color
- Guaranteed-color pairs, even with 6+ inheritance colors, will result
in a hatchling of the guaranteed color
- Black raptors **don't** have guaranteed or likely spawns if the
inheritance color list is less than 6 in length


## Changelog

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🆑
fix: When all six non-rare colors of raptor are cross-bred, a black
raptor now consistently spawns (unless a guaranteed color-combo
supersedes it).
/🆑

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code/modules/mob/living/basic/lavaland/raptor/_raptor.dm

@@ -280,7 +280,7 @@ GLOBAL_LIST_EMPTY(raptor_population)
 		return partner.raptor_color.guaranteed_crossbreeds[raptor_color.type]
 
 	// We've got all the colors in our family tree and aren't rolling a guarantee, bingo
-	if (length(inherited_stats.parent_colors | partner.inherited_stats.parent_colors | raptor_color.type | partner.raptor_color.type) == length(GLOB.raptor_colors))
+	if (length(inherited_stats.parent_colors | partner.inherited_stats.parent_colors | raptor_color.type | partner.raptor_color.type) >= (length(GLOB.raptor_colors) - 1))
 		return /datum/raptor_color/black
 
 	var/list/prob_list = list()