Integration tests must only go through the real file system/process manager/platform. The global indirection makes this code harder to understand than if it directly referred to the concrete instances that are being used.
Update the integration shard to use a const instance of a LocalFIleSystem, LocalProcessManager, and LocalPlatform. Remove global usage and apply testWithoutContext.
First pass at fixing #57985 and implementing #59602
This doesn't have enough metadata to be useful for IDEs yet, but it prevents the issue from getting worse while we iterate on it.
