Just got a bunch of instances of this suite timing out all on Windows agents. Could be a coincidence but seems unlikely.

**Build scan:**
https://gradle-enterprise.elastic.co/s/rvfpi7upehqjk/tests/:x-pack:plugin:esql:test/org.elasticsearch.xpack.esql.expression.function.scalar.nulls.CoalesceTests
**Reproduction line:**
```
null
```

**Applicable branches:**
main

**Reproduces locally?:**
Didn't try

**Failure history:**
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.xpack.esql.expression.function.scalar.nulls.CoalesceTests&tests.test=classMethod
**Failure excerpt:**
```
java.lang.Exception: Suite timeout exceeded (>= 2400000 msec).

  at __randomizedtesting.SeedInfo.seed([546AEE28130887AC]:0)

```
x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/AbstractFunctionTestCase.java
result.get(i).add(signature.get(i));
            }
        }
        return result;
    }
    private static Stream<List<DataType>> allPermutations(int argumentCount) {
        if (argumentCount == 0) {
            return Stream.of(List.of());
        }
        if (argumentCount > 4) {
            
            throw new IllegalArgumentException("would generate too many types");
        }
        Stream<List<DataType>> stream = representable().map(t -> List.of(t));
        for (int i = 1; i < argumentCount; i++) {
            stream = stream.flatMap(types -> representable().map(t -> append(types, t)));
        }
        return stream;
    }
    private static List<DataType> append(List<DataType> orig, DataType extra) {
        List<DataType> longer = new ArrayList<>(orig.size() + 1);
        longer.addAll(orig);
        longer.add(extra);
        return longer;
    }
    /**
     * Build a test case that asserts that the combination of parameter types is an error.
     */
    protected static TestCaseSupplier typeErrorSupplier(
        boolean includeOrdinal,