not possible to turn off devtools

**Problem**

In my config.toml I specifically turned of default-features to turn of devtools:

```
dioxus = { version = "0.6.1", features = ["router", "fullstack", "asset", "document", "file_engine", "hooks", "html", "launch", "logger", "macro", "mounted", "signals"], default-features = false }
```

But I still get it - as proven by deliberately putting an error in the crate that would trigger if devtools enabled.

I think I worked it out.

In https://github.com/DioxusLabs/dioxus/blob/main/Cargo.toml

We do an import of dioxus-full-stack:

```
dioxus-fullstack = { path = "packages/fullstack", version = "0.6.1" }
```

But we haven't turned off default-features.

Then in fullstack we process the the default features:

https://github.com/DioxusLabs/dioxus/blob/main/packages/fullstack/Cargo.toml

```
default = ["devtools", "document", "file_engine", "mounted"]
devtools = ["dioxus-web?/devtools", "dep:dioxus-devtools"]
```

I believe that this in turn enabled devtools on dioxus-web because the crate rules say that the feature set for a package is all the features merged.

Code is here: https://github.com/brianmay/dioxus-fs-demo

**Questionnaire**