Have "rust: cargo build" task work on global level (Not just for workspace)

I was able to create this debug launch config for my workspace by adding this config in .vscode/launch.json

{
	"name": "Rust",
	"type": "lldb",
	"request": "launch",
	"program": "${workspaceFolder}/target/debug/${workspaceFolderBasename}",
	"preLaunchTask": "rust: cargo build"
}

And it works!

However I want to use the same debug launch config everywhere. I added this config in the global settings.json file and when I run the Rust debug config, I get the following popup error

Could not find the task 'rust: cargo build'

Please add this task and perhaps other tasks to allow this simple debug config to work globally.

Start by locating where the rust: cargo build task is registered and how task availability differs between .vscode/launch.json and global settings.json. Verify the existing workspace launch configuration, then confirm that the same task resolves when the debug configuration is stored globally; the requested task, and any clearly related tasks, should work outside a workspace.