Remove River Conditions and Flow Tiles from viz_list.csv

[maggiejaenicke]

When the river conditions and flow tiles were added to their own respective carousels, they were filtered out from other places in the site using these two lines:
this.vizList_events = this.vizList_events_all.filter((viz) => !viz.title.includes("River Conditions"));
this.vizList_charts = this.vizList_charts_all.filter((viz) => !viz.title.includes("Flow cartogram"));

In the future, we may want to just remove these from the viz_list.csv, which will eliminate the need for these two lines of code.