Reorder dependencies' keys (#6967)

It doesn't make sense to only reorder the features array.

For example:

This makes it hard for me to compare the dependencies and features,
especially some crates have a really really long dependencies list.
```toml​
[dependencies]
c = "*"
a = "*"
b = "*"

[features]
std = [
  "a",
  "b",
  "c",
]
```

This makes my life easier.
```toml​
[dependencies]
a = "*"
b = "*"
c = "*"

[features]
std = [
  "a",
  "b",
  "c",
]
```

---------

Co-authored-by: Bastian Köcher <git@kchr.de>
Co-authored-by: command-bot <>