*: replace interface{} with any keyword

Everywhere including examples, external interop APIs, bindings generators
code and in other valuable places. A couple of `interface{}` usages are
intentionally left in the CHANGELOG.md, documentation and tests.

pkg/vm/stackitem/json_test.go

@@ -9,7 +9,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func getTestDecodeFunc(js string, expected ...interface{}) func(t *testing.T) {
+func getTestDecodeFunc(js string, expected ...any) func(t *testing.T) {
 	return func(t *testing.T) {
 		actual, err := FromJSON([]byte(js), 20)
 		if expected[0] == nil {