[Request] add option to disable even "bootstrappackageicon" by settings/constants

# Feature Request
I already set up a sitepackage and disabled the "bootstrappackageicon" manually by adding

```
page {
includeCSSLibs.bootstrappackageicon >
}
```

to the `setup.typoscript` but I anyway think it would be the best to add a variable to the constants or to the extension settings to be able to disable these icons as some people dont need them and they add one depth to the critical path of every site.

If someone exclude them he would make his page loaded faster.

Start by reviewing the setup.typoscript example that removes includeCSSLibs.bootstrappackageicon, then trace how constants or extension settings control that inclusion. Done means a documented option can disable the icon asset without requiring the manual TypoScript override, while the default behavior remains unchanged.

Written by the indexing model from the issue text.