### Problem Description

```
Caused by: java.lang.NullPointerException: Cannot invoke "java.lang.Integer.intValue()" because the return value of "org.elasticsearch.xpack.esql.planner.Layout.getChannel(org.elasticsearch.xpack.ql.expression.NameId)" is null
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.planProject(LocalExecutionPlanner.java:521)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:174)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.planExchangeSink(LocalExecutionPlanner.java:304)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:202)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:149)
        at org.elasticsearch.xpack.esql.plugin.ComputeService.runCompute(ComputeService.java:252)
        at org.elasticsearch.xpack.esql.plugin.ComputeService$DataNodeRequestHandler.lambda$messageReceived$5(ComputeService.java:422)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.action.ActionListener$2.onResponse(ActionListener.java:177)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.action.ActionListener.completeWith(ActionListener.java:305)
        at org.elasticsearch.xpack.esql.plugin.ComputeService.lambda$acquireSearchContexts$13(ComputeService.java:291)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.index.shard.IndexShard.ensureShardSearchActive(IndexShard.java:3926)
        at org.elasticsearch.xpack.esql.plugin.ComputeService.acquireSearchContexts(ComputeService.java:289)
        at org.elasticsearch.xpack.esql.plugin.ComputeService$DataNodeRequestHandler.messageReceived(ComputeService.java:420)
        at org.elasticsearch.xpack.esql.plugin.ComputeService$DataNodeRequestHandler.messageReceived(ComputeService.java:412)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.transport.RequestHandlerRegistry.processMessageReceived(RequestHandlerRegistry.java:75)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.transport.TransportService$6.doRun(TransportService.java:1019)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingAbstractRunnable.doRun(ThreadContext.java:983)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:26)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.common.util.concurrent.TimedRunnable.doRun(TimedRunnable.java:33)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingAbstractRunnable.doRun(ThreadContext.java:983)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:26)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
        at java.base/java.lang.Thread.run(Thread.java:1623)
```

### Steps to Reproduce

A very specific query (all commands must be used in that specific order) generates this NPE

```
from employees | limit 10 | rename first_name as somethingElse | stats var0 = avg(salary)
```

### Logs (if relevant)

_No response_
x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/optimizer/PhysicalPlanOptimizer.java
p.forEachExpression(NamedExpression.class, ne -> {
                        var attr = ne.toAttribute();
                        
                        if (ne instanceof Alias as) {
                            aliases.put(attr, as.child());
                            attributes.remove(attr);
                        } else {
                            if (aliases.containsKey(attr) == false) {
                                attributes.add(attr);
                            }
                        }
                    });
                    if (p instanceof RegexExtractExec ree) {
                        attributes.removeAll(ree.extractedFields());
                    }
                    if (p instanceof EnrichExec ee) {
                        for (NamedExpression enrichField : ee.enrichFields()) {
                            
                            attributes.remove(enrichField instanceof Alias a ? a.child() : enrichField);
                        }
                    }
                }
                if (p instanceof ExchangeExec exec) {
                    keepCollecting.set(FALSE);
                    var child = exec.child();
                    
                    if (child instanceof FragmentExec fragmentExec) {
                        var logicalFragment = fragmentExec.fragment();
                        
                        if (logicalFragment instanceof Aggregate == false) {