Kibana version:
latest code in main, since v7.16.3

Describe the bug:
When using a chart with legendMaxDepth set to 1 and the legend labels are identical, the legend width is set to about 1px.

Steps to reproduce:

1. Create a pie chart visualization from Kibana 7.16.3
2. Add 2 split slices with one filter each
3. Apply the same tag to each of the filters created in step 2
4. Make sure that the truncate legend text Pie setting is disabled.
5. Notice that the tag is displayed in the legend, but it appears as truncated, although the truncate setting is disabled.

Expected behavior:
Legend sizes appropriately

Screenshots (if relevant):