`SCMRepository` lifecycle is weird

[bpasero]

While finding leaks using Copilot I came across SCMRepository and how it gets passed in a DisposableStore:

vscode/src/vs/workbench/contrib/scm/common/scmService.ts

Line 199 in 55477c4

private readonly disposables: DisposableStore,

Which it then later disposes itself:

vscode/src/vs/workbench/contrib/scm/common/scmService.ts

Line 215 in 55477c4

this.disposables.dispose();

I think this is a bit against our rules for object lifecycle, rather I would have expected the SCMRepository to manage its own disposables and be a IDisposable.