Under certain circumstances, `.project` will cause projects to be recognized as nested.

### I confirm that...

- [X] I have searched the [issue tracker](https://github.com/doomemacs/doomemacs/issues), [documentation](https://docs.doomemacs.org), [FAQ](https://docs.doomemacs.org/-/faq), [Discourse](https://discourse.doomemacs.org), and [Google](https://google.com), in case this issue has already been reported/resolved.

- [X] I have read "[How to Debug Issues](https://doomemacs.org/d/how2debug)", and will use it to provide as much information about this issue as possible.

- [X] The issue can be reproduced on the **latest** available commit of Doom.

- [X] The issue can be reproduced on a stable release of Emacs, such as 27, 28, or 29. *(Unstable versions end in .50, .60, or .9x)*

### Expected behavior

`.project` won't be treated as project marker in doom.

### Current behavior

The java language server 'jdtls' will add `.project` in subdirectory when directory layout like this.
```
.
├── app
│   ├── build.gradle.kts
│   ├── .classpath
│   ├── .project <-----
│   └── src
├── gradlew
├── gradlew.bat
├── .project <-----
└── settings.gradle.kts
```
But doom will treat `.project` in the folder as a project marker. The app folder will became a known project in projectile.

https://github.com/doomemacs/doomemacs/blob/9620bb45ac4cd7b0274c497b2d9d93c4ad9364ee/lisp/doom-projects.el#L84-L88

I think the project marker `.project` is duplicated with `.projectile`, and the latter is more general.

### Steps to reproduce

1. Use `gradle init --type java-application --dsl kotlin --package local.duli --project-name test --java-version 17 --no-split-project` generate directory layout.
2. Use latest java language server `jdtls`.
2. open a java source file which in `app` folder.
3. `SPC p f` will see app treated as projectile project.

### System Information

https://pastebin.com/8ACQDc8U