src/vs/workbench/contrib/welcome/gettingStarted/browser/gettingStartedService.ts/GettingStartedService/unregisterExtensionWalkthroughContributions
class GettingStartedService:	private unregisterExtensionWalkthroughContributions(extension: IExtensionDescription) {
		if (!(extension.contributes?.walkthroughs?.length)) {
			return;
		}

		extension.contributes?.walkthroughs?.forEach(section => {
			const categoryID = extension.identifier.value + '#walkthrough#' + section.id;
			section.steps.forEach(step => {
				const fullyQualifiedID = extension.identifier.value + '#' + section.id + '#' + step.id;
				this.steps.delete(fullyQualifiedID);
			});
			this.gettingStartedContributions.delete(categoryID);
			this._onDidRemoveCategory.fire();
		});
	}