Refactor Function Declaration (#6283)

* Refactor Function Declaration

* Fix lint error

Author: FaybianB

token-metadata/js/src/state.ts

@@ -39,15 +39,15 @@ function isNonePubkey(buffer: Uint8Array): boolean {
 }
 
 // Pack TokenMetadata into byte slab
-export const pack = (meta: TokenMetadata): Uint8Array => {
+export function pack(meta: TokenMetadata): Uint8Array {
     // If no updateAuthority given, set it to the None/Zero PublicKey for encoding
     const updateAuthority = meta.updateAuthority ?? PublicKey.default;
     return tokenMetadataCodec.encode({
         ...meta,
         updateAuthority: updateAuthority.toBuffer(),
         mint: meta.mint.toBuffer(),
     });
-};
+}
 
 // unpack byte slab into TokenMetadata
 export function unpack(buffer: Buffer | Uint8Array): TokenMetadata {