Building a KMM shared library linked iOS project through Xcode on Apple M1 mac failing.

Since you are on M1 chip which is arm64 you need to switch this part of your config from

val iosTarget: (String, KotlinNativeTarget.() -> Unit) -> KotlinNativeTarget =
        if (System.getenv("SDK_NAME")?.startsWith("iphoneos") == true)
            ::iosArm64
        else
            ::iosX64
    iosTarget("ios") {}

to just

iosArm64("ios") {}

or you can build a fat version of it by doing the following

val buildXcFramework by tasks.registering {
    dependsOn("deleteXcFramework")
    group = "build"
    val mode = "Release"
    val frameworks = arrayOf("iosArm64", "iosX64")
        .map {
            kotlin.targets.getByName<org.jetbrains.kotlin.gradle.plugin.mpp.KotlinNativeTarget>(it).binaries.getFramework(
                mode
            )
        }
    inputs.property("mode", mode)
    dependsOn(frameworks.map { it.linkTask })
    doLast { buildXcFramework(frameworks) }
}

fun Task.buildXcFramework(frameworks: List<org.jetbrains.kotlin.gradle.plugin.mpp.Framework>) {
    val buildArgs: () -> List<String> = {
        val arguments = mutableListOf("-create-xcframework")
        frameworks.forEach {
            arguments += "-framework"
            arguments += "${it.outputDirectory}/$frameworkName.framework"
        }
        arguments += "-output"
        arguments += xcFrameworkPath
        arguments
    }
    exec {
        executable = "xcodebuild"
        args = buildArgs()
    }
}