Revert "Add event_loop_group struct import"

This reverts commit 0c81ae3.

Author: lauzadis

aws-crt-kotlin/native/src/aws/sdk/kotlin/crt/io/EventLoopGroupNative.kt

@@ -9,7 +9,6 @@ import aws.sdk.kotlin.crt.*
 import aws.sdk.kotlin.crt.Allocator
 import aws.sdk.kotlin.crt.util.ShutdownChannel
 import aws.sdk.kotlin.crt.util.shutdownChannel
-import cnames.structs.aws_event_loop_group
 import kotlinx.cinterop.*
 import libcrt.*