fix: remove duplicate loop

[G-Rath]

This loop is the exact same as this.#idealTreePrune:

cli/workspaces/arborist/lib/arborist/build-ideal-tree.js

Lines 1517 to 1523 in b7758d7

	#idealTreePrune () {
	for (const node of this.idealTree.inventory.values()) {
	if (node.extraneous) {
	node.parent = null
	}
	}
	}

I'm 98% sure it's a left-over from a refactor that intended to encapsulate the logic so it can be reused elsewhere

References

[wraithgar]

Even worse it was part of a code cleanup that I apparently hit "paste" into somehow as I was doing it. Good catch.

#6393