It's really annoying, and I can't dev properly on Quilt while this is happening. I'm going to have to manually exclude it.

Workaround

Include this exclusion in a block next to the inclusion of modmenu like this.

modRuntimeOnly("com.terraformersmc", "modmenu", "7.1.0") {
	exclude(group = "net.fabricmc.fabric-api")
	exclude(group = "net.fabricmc")
}