Standalone code not truly standalone

**What version of Ajv are you using? Does the issue happen if you use the latest version?**
* v8.17.1
* Yes

**Ajv options object**

```javascript

```

**JSON Schema**

```json
N/A
```

**Sample data**

```json
const Error0 = require("ajv/dist/runtime/validation_error").default;
```

**Your code**

```javascript

```

**Validation result, data AFTER validation, error messages**

```

```

**What results did you expect?**
The standalone code should be truly standalone and portable. With this require statement added, it is no longer truly standalone:

https://github.com/ajv-validator/ajv/blob/69568d08564303e2c32a2de61feb833b41075f96/lib/compile/index.ts#L120-L125

**Are you going to resolve the issue?**