feat: export withCache

Author: jxom

.changeset/tender-cooks-agree.md

@@ -0,0 +1,5 @@
+---
+"viem": patch
+---
+
+Exported `withCache`.

src/index.ts

@@ -1592,6 +1592,7 @@ export {
   type EncodePackedErrorType,
   encodePacked,
 } from './utils/abi/encodePacked.js'
+export { withCache } from './utils/promise/withCache.js'
 export {
   type WithRetryErrorType,
   withRetry,