Update test assertion library for better errors (#74863)
Update test assertion library for better errors (#74863)

This updates the `mapmatcher` test assertion library that we use to pick
up a fix for error messages when you expect a `Map` or a `List` but get
*nothing*. Now it says something sensible like:

```
  key: expected a map but was <missing>
```

instead of the confusing

```
  key: expected a map containing
    <the stuff the map was expected to contain> but was missing
```

Relates to #74721

Co-authored-by: Elastic Machine <aba0ff71c61dffd83d6f2c8185bc4b064b23c44a@users.noreply.github.com>
GlenRSmith/elasticsearch,GlenRSmith/elasticsearch,GlenRSmith/elasticsearch,GlenRSmith/elasticsearch,GlenRSmith/elasticsearch