useDefault option not working

**What version of Ajv are you using? Does the issue happen if you use the latest version?**
8.11.0
**Ajv options object**

```javascript
{
useDefaults: "empty", // 'empty' or true
allErrors: true,
coerceTypes: true,
parseDate: true,
}
```

**JSON Schema**

```json
{
"type": "object",
"properties": {
"disabled": {
"type": "boolean",
"default": false,
"description": "Disable real redis connection for use a mock"
},
"clientOptions": {
"type": "object",
"properties": {
"host": { "type": "string", "default": "localhost" },
"port": { "type": "number" },
"auth_pass": { "type": "string" }
},
"required": ["host"],
"description": "Client options for redis connection"
}
},
"oneOf": [
{ "properties": { "disabled": { "const": true } } },
{ "required": ["clientOptions"] }
],
"required": ["disabled"]
}
```

**Sample data**

Sample 1 (OK, just for test)
```json
{ "disabled": false }
```
Sample 2 (ISSUED)
```json
{ }
```

**Your code**

```javascript
const Ajv = require("ajv");

const validator = new Ajv(options);

// Validation 1
const result1 = validator.validate(schema, data1); // (SAMPLE 1) Expected false and its ok

// Validation 2 Here its the problem
const result2 = validator.validate(schema, data2); // (SAMPLE 2) Expected false but returns true ??
```

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

```
SAMPLE 1 OK!
// valid: false
[
{
instancePath: '/disabled',
schemaPath: '#/oneOf/0/properties/disabled/const',
keyword: 'const',
params: { allowedValue: true },
message: 'must be equal to constant'
},
{
instancePath: '',
schemaPath: '#/oneOf/1/required',
keyword: 'required',
params: { missingProperty: 'clientOptions' },
message: "must have required property 'clientOptions'"
},
{
instancePath: '',
schemaPath: '#/oneOf',
keyword: 'oneOf',
params: { passingSchemas: null },
message: 'must match exactly one schema in oneOf'
}
]

SAMPLE 2 UNEXPECTED!!
// valid: true
nulll
```

**What results did you expect?**
With the `useDefault` property specified, i expect the behaviour for Sample1 and Sample2 would be the same and both fails cause takes the same `false` value
Expect same result when `disabled` its `false` (Sample1 its explicit and Sample2 its by default)

**Are you going to resolve the issue?**
Not sure