Remove unused code from Gannt View (#8302)
Remove unused code from Gannt View (#8302)

After https://github.com/apache/airflow/pull/8220 we do not need task_types and extra_links variables
danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,wooga/airflow,cfei18/incubator-airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,mrkm4ntr/incubator-airflow,sekikn/incubator-airflow,nathanielvarona/airflow,sekikn/incubator-airflow,apache/airflow,nathanielvarona/airflow,nathanielvarona/airflow,sekikn/incubator-airflow,DinoCow/airflow,danielvdende/incubator-airflow,wooga/airflow,dhuang/incubator-airflow,lyft/incubator-airflow,apache/airflow,DinoCow/airflow,apache/airflow,dhuang/incubator-airflow,airbnb/airflow,Acehaidrey/incubator-airflow,lyft/incubator-airflow,airbnb/airflow,apache/incubator-airflow,mrkm4ntr/incubator-airflow,DinoCow/airflow,apache/airflow,wooga/airflow,sekikn/incubator-airflow,nathanielvarona/airflow,apache/incubator-airflow,bolkedebruin/airflow,mrkm4ntr/incubator-airflow,bolkedebruin/airflow,cfei18/incubator-airflow,mistercrunch/airflow,danielvdende/incubator-airflow,bolkedebruin/airflow,danielvdende/incubator-airflow,mrkm4ntr/incubator-airflow,bolkedebruin/airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,wooga/airflow,apache/incubator-airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,airbnb/airflow,cfei18/incubator-airflow,airbnb/airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,cfei18/incubator-airflow,apache/airflow,nathanielvarona/airflow,dhuang/incubator-airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,dhuang/incubator-airflow,apache/airflow,apache/incubator-airflow,DinoCow/airflow,cfei18/incubator-airflow,cfei18/incubator-airflow,bolkedebruin/airflow,mistercrunch/airflow