src/vs/workbench/api/common/extHostExtensionService.ts/Extension/activate
class Extension:	async activate(): Promise<T> {
		if (this.isFromDifferentExtensionHost) {
			throw new Error('Cannot activate foreign extension'); // TODO@alexdima support this
		}
		await this.#extensionService.activateByIdWithErrors(this.#identifier, { startup: false, extensionId: this.#originExtensionId, activationEvent: 'api' });
		return this.exports;
	}