Update index.js

index.js

@@ -76,7 +76,7 @@ export function int64ToFloat16(int64Value) {
   }
 }
 
-export function float16ToInt64(float16Value: number): bigint {
+export function float16ToInt64(float16Value) {
   // Extract components from float16
   const sign = (float16Value & 0x8000) >> 15;
   const exponent = (float16Value & 0x7c00) >> 10;