[Rust] Stuck in the `roots scanned` state

### Checklist

- [x] I have searched through the AstroNvim documentation
- [x] I have searched through the existing issues of this project
- [x] I have searched the existing issues of plugins related to this issue
- [x] I can replicate the bug with the minimal `repro.lua` provided below

### Neovim version (nvim -v)

0.12.1

### Operating system/version

macOS

### Terminal/GUI

Ghostty

### Describe the bug

There is an issue with the current `rustaceanvim` configuration. When entering a `Rust` project, it may get stuck in the `roots scanned` state. The following configuration needs to be added to resolve this. I hope the maintainers of the `Rust` package can consider fixing this.

## Solution

```lua
return {
"mrcjkb/rustaceanvim",
opts = function(_, opts)
return require("astrocore").extend_tbl(opts, {
server = {
default_settings = {
["rust-analyzer"] = {
files = {
exclude = {
".direnv",
".git",
".jj",
".github",
".gitlab",
"bin",
"node_modules",
"target",
"venv",
".venv",
},
-- Avoid Roots Scanned hanging, see https://github.com/rust-lang/rust-analyzer/issues/12613#issuecomment-2096386344
watcher = "client",
},
},
},
},
})
end,
}

```

### Steps to Reproduce

null

### Expected behavior

null

### Screenshots

_No response_

### Additional Context

_No response_

### Minimal configuration

```Lua
null
```

Start by locating the AstroNvim rustaceanvim plugin configuration and reviewing how its rust-analyzer settings are assembled. Reproduce the issue in a Rust project using the provided configuration, then verify that entering the project no longer remains stuck in the “roots scanned” state.

Written by the indexing model from the issue text.