chore: don't ask for api key if it already exists (#4549)

### Description

CLI will ask for API keys even if your (local) registry already includes
the API key. This PR fixes that.

Can't say i love the current code setup, it seems to me that it should
be more like a pass on the registry and filter chains that don't have
api keys, prompt for the api key and then persist that in the registry
if its writable. But since i have so little context, kept it mostly this
way to accomplish the desired product experience.

typescript/cli/src/context/context.ts

@@ -195,6 +195,10 @@ export async function getOrRequestApiKeys(
   const apiKeys: ChainMap<string> = {};
 
   for (const chain of chains) {
+    if (chainMetadata[chain]?.blockExplorers?.[0]?.apiKey) {
+      apiKeys[chain] = chainMetadata[chain]!.blockExplorers![0]!.apiKey!;
+      continue;
+    }
     const wantApiKey = await confirm({
       default: false,
       message: `Do you want to use an API key to verify on this (${chain}) chain's block explorer`,