fix: resolve type error by explicitly typing headers as HeadersInit (#…

…3009)

* fix: resolve type error by explicitly typing headers as HeadersInit

This commit addresses a type error in `src/utils/ccip.ts` where the `headers` object was not assignable to the `HeadersInit` type. The issue occurred due to the optional `'Content-Type'` property. Explicitly typing `headers` as `HeadersInit` resolves the type incompatibility, ensuring compatibility with the `fetch` API.

- Explicitly typed `headers` as `HeadersInit`.
- Resolved the optional `'Content-Type'` property type conflict.
- Verified functionality by running the test suite.

This fix improves type safety and aligns with TypeScript's strict requirements.

* Create fast-timers-crash.md

---------

Co-authored-by: jxom <[email protected]>

.changeset/fast-timers-crash.md

@@ -0,0 +1,5 @@
+---
+"viem": patch
+---
+
+Resolved type error by explicitly typing `headers` as `HeadersInit` in CCIP.

src/utils/ccip.ts

@@ -136,7 +136,7 @@ export async function ccipRequest({
     const url = urls[i]
     const method = url.includes('{data}') ? 'GET' : 'POST'
     const body = method === 'POST' ? { data, sender } : undefined
-    const headers =
+    const headers: HeadersInit =
       method === 'POST' ? { 'Content-Type': 'application/json' } : {}
 
     try {