Describe the bug
The EuiInMemoryTable assigns the euiTableRow-isSelectable class to non-selectable rows.

Impact and severity
The impact is largely felt when writing automated tests. For example, this routine in Kibana's functional test code is no longer accurate since isSelectable is being applied to all rows. I don't think this is high impact since the test can always examine the checkboxes themselves.

Environment and versions

• EUI version: v93.0.0
• React version: 17.0.2

To Reproduce
Steps to reproduce the behavior:

1. Go to https://eui.elastic.co/#/tabular-content/in-memory-tables#in-memory-table-selection
2. Load the rows in the example
3. Inspect the dom

Expected behavior
I would expect isSelectable CSS class to only be applied to rows for which selection.selectable returned true 🤷‍♂️