sankey_test: increase position tolerance to run on CI
sankey_test: increase position tolerance to run on CI

etpinard/plotly.js,plotly/plotly.js,etpinard/plotly.js,plotly/plotly.js,aburato/plotly.js,aburato/plotly.js,plotly/plotly.js,plotly/plotly.js,etpinard/plotly.js