Use fastArrayBufferToByteArray in TestWasmResourceReader too (#5551)

I missed this when doing
#5550

## Testing
N/A

## Release Notes
N/A

Author: eymar

components/resources/library/src/wasmJsMain/kotlin/org/jetbrains/compose/resources/ResourceReader.wasmJs.kt

@@ -4,12 +4,9 @@ import kotlinx.browser.window
 import kotlinx.coroutines.await
 import org.khronos.webgl.ArrayBuffer
 import org.khronos.webgl.Int8Array
-import org.w3c.fetch.Response
 import org.w3c.files.Blob
 import org.w3c.xhr.XMLHttpRequest
 import kotlin.js.Promise
-import kotlin.wasm.unsafe.UnsafeWasmMemoryApi
-import kotlin.wasm.unsafe.withScopedMemoryAllocator
 
 @JsFun(
     """ (src, size, dstAddr) => {
@@ -85,24 +82,11 @@ private object TestWasmResourceReader : ResourceReader {
         request.overrideMimeType("text/plain; charset=x-user-defined")
         request.send()
         if (request.status == 200.toShort()) {
-            return requestResponseAsByteArray(request).asByteArray()
+            return fastArrayBufferToByteArray(requestResponseAsByteArray(request).buffer)
         }
         println("Request status is not 200 - $resPath, status: ${request.status}")
         throw MissingResourceException(resPath)
     }
-
-    private fun Int8Array.asByteArray(): ByteArray {
-        val array = this
-        val size = array.length
-
-        @OptIn(UnsafeWasmMemoryApi::class)
-        return withScopedMemoryAllocator { allocator ->
-            val memBuffer = allocator.allocate(size)
-            val dstAddress = memBuffer.address.toInt()
-            jsExportInt8ArrayToWasm(array, size, dstAddress)
-            ByteArray(size) { i -> (memBuffer + i).loadByte() }
-        }
-    }
 }
 
 // For blocking XmlHttpRequest the response can be only in text form, so we convert it to bytes manually