install.py fails on fresh clone due to broken submodule references

[m3rchant-man]

Description
When following the quick setup instructions and running install.py on a fresh clone of the repository, the installation fails.

Reproduction

1. git clone https://github.com/OpenChamp/client.git
2. cd client
3. python3 ./install.py

Expected
The script should download all dependencies, and compile the project.

Actual
The script fails to install godot-cpp and default_assets submodules

$ python3 ./install.py
Submodule 'default_assets' (https://github.com/OpenChamp/default_assets) registered for path 'default_assets'
Submodule 'extensions/godot-cpp' (https://github.com/godotengine/godot-cpp) registered for path 'extensions/godot-cpp'
Cloning into '/Project/client/default_assets'...
Cloning into '/Project/client/extensions/godot-cpp'...
fatal: remote error: upload-pack: not our ref ec38cc5ccce0d01db71bc560ce07b4fc2f2477b1
fatal: Fetched in submodule path 'default_assets', but it did not contain ec38cc5ccce0d01db71bc560ce07b4fc2f2477b1. Direct fetching of that commit failed.
/usr/bin/python3: can't open file '/Project/client/default_assets/manifests.py': [Errno 2] No such file or directory
Failed to get current tag
Compiling extension
{'build_mode': 'debug', 'target_arch': 'x86_64', 'build_dir': None, 'build_system': '-GNinja', 'set_linker': '', 'skip_setup': False, 'jobs': 0}
Building natively for the host architecture (x86_64)
-- The CXX compiler identification is GNU 13.3.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Error at CMakeLists.txt:61 (add_subdirectory):
  The source directory

   /Project/client/extensions/godot-cpp

  does not contain a CMakeLists.txt file.


-- Configuring incomplete, errors occurred!
Failed to run the setup command
CompletedProcess(args=['cmake', '-DCMAKE_BUILD_TYPE=Debug', '-B', 'extensions/build_x86_64_debug', '-GNinja', 'extensions'], returncode=1)

[m3rchant-man]

Pull request #105 forces the script to halt at time of error.