gunt-babel Warning: Using removed Babel 6 option: .sourceMapTarget

my grunt-babel it is not working for a reason, not sure what it is going on, can someone help me?

package.json

```
"devDependencies": {
"@babel/core": "*",
"babel-core": "*",
"babel-loader": "*",
"@babel/preset-env": "*",
"grunt": "*",
"grunt-babel": "*",
"load-grunt-tasks": "*"
}
```
}

gruntfile.js

```
var babel;
config.babel = babel = {};

config.babel = {
options: {
sourceMap: true,
inputSourceMap: grunt.file.readJSON('public/myapp.production.js.map'),
presets: ['@babel/preset-env']
},
dist: {
files: {
'public/test-babel-main.js': 'public/test-babel-main.js'
}
}
};
```

after run: grunt babel

```
Running "babel:dist" (babel) task
Warning: Using removed Babel 6 option: .sourceMapTarget - The `sourceMapTarget` option has been removed because it makes more sense for the tooling that calls Babel to assign `map.file` themselves. Use --force to continue.

Aborted due to warnings.

Execution Time (2020-11-30 15:59:33 UTC-0)
loading tasks 843ms ███████████████████████████████████████████████ 99%
Total 848ms
```

Start by reviewing package.json and gruntfile.js, then run `grunt babel` to reproduce the warning. Check how the configured Babel options and the listed Babel packages relate to the reported removed `.sourceMapTarget` option; done means the task completes without this warning.

Written by the indexing model from the issue text.