`Ec2MetadataClient` IMDSv2 401 Unauthorized HTTP Status Code Exceptions

### Describe the bug

Using `Ec2MetadataClient` to query the IMDSv2 service on an EC2 instance will eventually throw an `SdkClientException` for a `401 Unauthorized` HTTP status code as shown [here](https://github.com/aws/aws-sdk-java-v2/blob/61d16e083a27a146665aec19f14bfd31e54e9f83/core/imds/src/main/java/software/amazon/awssdk/imds/internal/DefaultEc2MetadataClient.java#L172).

### Regression Issue

- [ ] Select this option if this issue appears to be a regression.

### Expected Behavior

This reproduction example should not print any errors. The `Ec2MetadataClient` should not use stale tokens, which could be the cause of the `401 Unauthorized` response.

### Current Behavior

Let it run long enough and the reproduction example produces the following log:
```
DEBUG 2024-12-28 18:40:33.451 UTC [main] software.amazon.awssdk.core.internal.http.loader.ClasspathSdkHttpServiceProvider - The HTTP implementation loaded is software.amazon.awssdk.http.apache.ApacheSdkHttpService@4b45a2f5
INFO 2024-12-28 18:40:33.802 UTC [main] App - Started.
DEBUG 2024-12-28 18:40:33.804 UTC [pool-1-thread-1] software.amazon.awssdk.utils.cache.CachedSupplier - (Ec2MetadataClient()) Cached value is stale and will be refreshed.
DEBUG 2024-12-28 18:40:33.805 UTC [pool-1-thread-1] software.amazon.awssdk.utils.cache.CachedSupplier - (Ec2MetadataClient()) Refreshing cached value.
DEBUG 2024-12-28 18:40:33.886 UTC [pool-1-thread-1] software.amazon.awssdk.utils.cache.CachedSupplier - (Ec2MetadataClient()) Successfully refreshed cached value. Next Prefetch Time: +1000000000-12-31T23:59:59.999999999Z. Next Stale Time: 2024-12-28T18:41:33.886487462Z
INFO 2024-12-28 18:40:33.912 UTC [pool-1-thread-1] App - MetadataResponse(body=InService)
INFO 2024-12-28 18:40:48.803 UTC [pool-1-thread-1] App - MetadataResponse(body=InService)
INFO 2024-12-28 18:41:03.803 UTC [pool-1-thread-1] App - MetadataResponse(body=InService)
INFO 2024-12-28 18:41:18.803 UTC [pool-1-thread-1] App - MetadataResponse(body=InService)
DEBUG 2024-12-28 18:41:33.807 UTC [pool-1-thread-1] software.amazon.awssdk.imds.internal.DefaultEc2MetadataClient - Metadata request response body:
DEBUG 2024-12-28 18:41:33.811 UTC [pool-1-thread-1] software.amazon.awssdk.imds.internal.DefaultEc2MetadataClient - Error while executing EC2Metadata request. Total attempts: 1. The requested metadata at path '/latest/meta-data/autoscaling/target-lifecycle-state' returned Http code 401
ERROR 2024-12-28 18:41:33.812 UTC [pool-1-thread-1] java.lang.Throwable - software.amazon.awssdk.core.exception.SdkClientException: The requested metadata at path '/latest/meta-data/autoscaling/target-lifecycle-state' returned Http code 401
ERROR 2024-12-28 18:41:33.812 UTC [pool-1-thread-1] java.lang.Throwable - at software.amazon.awssdk.core.exception.SdkClientException$BuilderImpl.build(SdkClientException.java:111)
ERROR 2024-12-28 18:41:33.812 UTC [pool-1-thread-1] java.lang.Throwable - at software.amazon.awssdk.imds.internal.DefaultEc2MetadataClient.sendRequest(DefaultEc2MetadataClient.java:178)
ERROR 2024-12-28 18:41:33.812 UTC [pool-1-thread-1] java.lang.Throwable - at software.amazon.awssdk.imds.internal.DefaultEc2MetadataClient.get(DefaultEc2MetadataClient.java:123)
ERROR 2024-12-28 18:41:33.812 UTC [pool-1-thread-1] java.lang.Throwable - at App.lambda$new$0(AppManager.java:58)
ERROR 2024-12-28 18:41:33.812 UTC [pool-1-thread-1] java.lang.Throwable - at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:572)
ERROR 2024-12-28 18:41:33.812 UTC [pool-1-thread-1] java.lang.Throwable - at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:358)
ERROR 2024-12-28 18:41:33.812 UTC [pool-1-thread-1] java.lang.Throwable - at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:305)
ERROR 2024-12-28 18:41:33.812 UTC [pool-1-thread-1] java.lang.Throwable - at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
ERROR 2024-12-28 18:41:33.812 UTC [pool-1-thread-1] java.lang.Throwable - at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
ERROR 2024-12-28 18:41:33.813 UTC [pool-1-thread-1] java.lang.Throwable - at java.base/java.lang.Thread.run(Thread.java:1583)
DEBUG 2024-12-28 18:41:48.800 UTC [pool-1-thread-1] software.amazon.awssdk.utils.cache.CachedSupplier - (Ec2MetadataClient()) Cached value is stale and will be refreshed.
DEBUG 2024-12-28 18:41:48.801 UTC [pool-1-thread-1] software.amazon.awssdk.utils.cache.CachedSupplier - (Ec2MetadataClient()) Refreshing cached value.
DEBUG 2024-12-28 18:41:48.804 UTC [pool-1-thread-1] software.amazon.awssdk.utils.cache.CachedSupplier - (Ec2MetadataClient()) Successfully refreshed cached value. Next Prefetch Time: +1000000000-12-31T23:59:59.999999999Z. Next Stale Time: 2024-12-28T18:42:48.803994713Z
INFO 2024-12-28 18:41:48.806 UTC [pool-1-thread-1] App - MetadataResponse(body=InService)
INFO 2024-12-28 18:42:03.803 UTC [pool-1-thread-1] App - MetadataResponse(body=InService)
```

### Reproduction Steps

This reproduction example uses a short token TTL, but longer TTLs produce the same errors.
```java
Ec2MetadataClient ec2Metadata = Ec2MetadataClient.builder().tokenTtl(ofMinutes(1)).build();
newSingleThreadScheduledExecutor().scheduleAtFixedRate(() -> {
try {
System.out.println(ec2Metadata.get("/latest/meta-data/autoscaling/target-lifecycle-state"));
} catch (Exception exception) {
exception.printStackTrace();
}
}, 0, 15, SECONDS);
```

### Possible Solution

[This line](https://github.com/aws/aws-sdk-java-v2/blob/61d16e083a27a146665aec19f14bfd31e54e9f83/core/imds/src/main/java/software/amazon/awssdk/imds/internal/DefaultEc2MetadataClient.java#L120) checks if the current IMDSv2 token is expired before sending the request to the IMDS service, but there appears to be some sort of issue that causes a stale token to be used for the IMDS request. The subsequent call after a `401 Unauthorized` exception will refresh the token before the IMDS request, so I suspect a potential race condition (there may need to be some buffer time between the IMDS token TTL and the JVM-cached TTL) or some other timing issue.

### Additional Information/Context

_No response_

### AWS Java SDK version used

2.29.43

### JDK version used

OpenJDK 64-Bit Server VM Corretto-21.0.5.11.1

### Operating System and version

Ubuntu 24.04.1 LTS