Why are dependencies still present in the installer path after removal?

Why are dependencies that are removed from the `composer.json` file still present in the installer path? Is this the intended behavior, or is there a solution to remove the dependencies from the installer path as well?

First, I will add a dependency to the installer path.

```diff
{
"require": {
"php": "^8.2"
},
"extra": {
"installer-paths": {
"public/mu-plugins/{$name}/": [
"type:wordpress-muplugin",
+ "wpackagist-plugin/bugsnag"
]
}
}
```

Then, I will install the plugin by using the `composer require` command.

```sh
composer require wpackagist-plugin/bugsnag
```

The dependency has been installed correctly in the installer path. Next, I remove it from the `composer.json` file.

```diff
{
"require": {
"php": "^8.2",
- "wpackagist-plugin/bugsnag": "^1.0"
},
"extra": {
"installer-paths": {
"public/mu-plugins/{$name}/": [
"type:wordpress-muplugin",
- "wpackagist-plugin/bugsnag"
]
}
}
```

Then I run `composer update` in the root of the project.

```sh
composer update
```

The dependency has been removed from the `vendor` directory but remains in the installer path.

Related issues: #82 #519