The ES|QL `COUNT_DISTINCT` function fails with an `illegal agg type: text` error when it's run on a `text` field. It's fine with `keyword` fields. Compare to for example `COUNT`, which runs fine on text fields:

```
PUT test/_doc/1
{
  "foo": "bar"
}

# This fails with illegal agg type: text:
POST /_query
{
  "query": """
    FROM test
    | STATS count = COUNT_DISTINCT(foo)
  """
}

# This works:
POST /_query
{
  "query": """
    FROM test
    | STATS count = COUNT_DISTINCT(foo.keyword)
  """
}

# COUNT is fine with text fields:
POST /_query
{
  "query": """
    FROM test
    | STATS count = COUNT(foo)
  """
}
```

Full error message:

```
{
  "error": {
    "root_cause": [
      {
        "type": "esql_illegal_argument_exception",
        "reason": "illegal agg type: text"
      }
    ],
    "type": "esql_illegal_argument_exception",
    "reason": "illegal agg type: text"
  },
  "status": 500
}
```
x-pack/plugin/esql/src/internalClusterTest/java/org/elasticsearch/xpack/esql/action/EsqlActionIT.java
assertEquals(10L, getValuesList(results).get(0).get(0));
            assertEquals(55000L, getValuesList(results).get(0).get(1));
        }
        try (var results = run("from test_index_patterns_1*,test_index_patterns_2* | stats count(data), sum(count)")) {
            assertEquals(1, getValuesList(results).size());
            assertEquals(10L, getValuesList(results).get(0).get(0));
            assertEquals(55000L, getValuesList(results).get(0).get(1));
        }
        try (var results = run("from test_index_patterns_*,-test_index_patterns_1 | stats count(data), sum(count)")) {
            assertEquals(1, getValuesList(results).size());
            assertEquals(10L, getValuesList(results).get(0).get(0));
            assertEquals(105000L, getValuesList(results).get(0).get(1));
        }
        try (var results = run("from * | stats count(data), sum(count)")) {
            assertEquals(1, getValuesList(results).size());
            assertEquals(55L, getValuesList(results).get(0).get(0));
            assertEquals(121720L, getValuesList(results).get(0).get(1));
        }
        try (var results = run("from test_index_patterns_2 | stats count(data), sum(count)")) {
            assertEquals(1, getValuesList(results).size());
            assertEquals(5L, getValuesList(results).get(0).get(0));
            assertEquals(40000L, getValuesList(results).get(0).get(1));
        }
    }
    public void testOverlappingIndexPatterns() throws Exception {
        String[] indexNames = { "test_overlapping_index_patterns_1", "test_overlapping_index_patterns_2" };
        assertAcked(
            client().admin()
                .indices()
                .prepareCreate("test_overlapping_index_patterns_1")