refactor: replace interface{} with any (Go 1.18+)

README.md

@@ -50,7 +50,7 @@ BenchmarkDecoderNextToken/pkgjson/sample.json.gz-16                 2032
 BenchmarkDecoderNextToken/encodingjson/sample.json.gz-16             332           3574484 ns/op         192.33 MB/s      759685 B/op      26643 allocs/op
 ```
 
-Decoding into an `interface{}` this package is 40-50% faster than `encoding/json`:
+Decoding into an `any` this package is 40-50% faster than `encoding/json`:
 ```
 BenchmarkDecoderDecodeInterfaceAny/pkgjson/canada.json.gz-16                  43          27181309 ns/op          82.82 MB/s     8747225 B/op     281408 allocs/op
 BenchmarkDecoderDecodeInterfaceAny/encodingjson/canada.json.gz-16             30          36930290 ns/op          60.95 MB/s    20647699 B/op     392553 allocs/op

fuzz.go

@@ -31,7 +31,7 @@ func Fuzz(data []byte) int {
 		}
 		return 0
 	}
-	var i interface{}
+	var i any
 	dec = NewDecoder(bytes.NewReader(data))
 	err := dec.Decode(&i)
 	if err != nil {