non-project file, only JDK classes are added to its build path

[provide a description of the issue]

Environment

• Operating System: window 11
• JDK version: 17
• Visual Studio Code version: 1.90
• Java extension version: v0.27.0

Steps To Reproduce

1. [step 1] clone project
2. [step 2] set datasource (/redisChat/src/main/resources/application.yml)
   (I was using h2 in this project.)
3. [step 3] run redisChatApplication.java

[Please attach a sample project reproducing the error]
https://github.com/0gon/hung_chit_chat
[Please attach logs]

Exception in thread "main" java.lang.Error: Unresolved compilation problem: 
        SpringApplication cannot be resolved

        at com.redis.redisChat.demo.RedisChatApplication.main(RedisChatApplication.java:10)

Current Results

Added two modules to practice the msa method. kafkaChat, redischat.
It works fine on the pc that created the project, but I try to clone it and run it on another pc, so I can't get spring boot dependency.

Estimated results

Maybe when I clone it, I don't think I recognize the folder as a module or project, but as a simple folder.

I've looked in many directions. But I'm sorry I'm a beginner, and I don't know any more because I lack clues.

Additional Informations

Start with the linked hung_chit_chat project, its modules, and redisChat/src/main/resources/application.yml; then run RedisChatApplication.java in VS Code using the reported JDK and extension versions. Compare the cloned project's behavior with the reported unresolved SpringApplication error. Done means the cause of the missing Spring Boot dependency or project recognition is documented and the cloned application can resolve its dependencies.