chore(lib): validate inputs before locking (#2148)

The PR #2140 introduced a
locking around a cache. Some parts of the critical section seem
unrelated to the locking and can be done before without changing the
read semantics (because this check happened after the cache read
before).

issue: none

lib/contracts/address.go

@@ -114,6 +114,11 @@ var (
 
 // GetAddresses returns the contract addresses for the given network.
 func GetAddresses(ctx context.Context, network netconf.ID) (Addresses, error) {
+	ver, err := version(ctx, network)
+	if err != nil {
+		return Addresses{}, err
+	}
+
 	addrsCache.mu.Lock()
 	defer addrsCache.mu.Unlock()
 
@@ -122,11 +127,6 @@ func GetAddresses(ctx context.Context, network netconf.ID) (Addresses, error) {
 		return addrs, nil
 	}
 
-	ver, err := version(ctx, network)
-	if err != nil {
-		return Addresses{}, err
-	}
-
 	addrs = Addresses{
 		Create3Factory: create3Factory(network),
 		AVS:            avs(network),