### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When requesting a  Complete operation at the end of a multi part upload, the parts have to be sorted in ascending order of part number.
AWS S3 issues an error if it is not the case. localstack does not generate such error (although, its log issues warnings)/

### Expected Behavior

Complete should generate an error

### How are you starting LocalStack?

With the `localstack` script

### Steps To Reproduce

localstack start

Buggy software extract (simplified)
```golang
	wg := errgroup.Group{}
	for i := 0; i < 3; i++ {
		wg.Go(func() error {
			rd, err := os.Open(source)
			if err != nil {
				return err
			}
			return u.Upload(rd, i, 10*_cMB)  // uploads and stores for part i
		})
	}
	err :=  wg.Wait()
if err != nil {
...
}
err = u.Complete()
// as using i inside the routines, all the four parts will have the same value 3
```

### Environment

```markdown
- OS:Ubuntu 20.04
- LocalStack: latest pro
```


### Anything else?

_No response_
Grants: Optional[Grants]
    Owner: Optional[Owner]
class AccessControlTranslation(TypedDict, total=False):
    Owner: OwnerOverride
AllowedHeaders = List[AllowedHeader]
AllowedMethods = List[AllowedMethod]
AllowedOrigins = List[AllowedOrigin]
class Tag(TypedDict, total=False):
    Key: ObjectKey
    Value: Value
TagSet = List[Tag]
class AnalyticsAndOperator(TypedDict, total=False):
    Prefix: Optional[Prefix]
    Tags: Optional[TagSet]
class AnalyticsS3BucketDestination(TypedDict, total=False):
    Format: AnalyticsS3ExportFileFormat
    BucketAccountId: Optional[AccountId]
    Bucket: BucketName
    Prefix: Optional[Prefix]
class AnalyticsExportDestination(TypedDict, total=False):
    S3BucketDestination: AnalyticsS3BucketDestination
class StorageClassAnalysisDataExport(TypedDict, total=False):
    OutputSchemaVersion: StorageClassAnalysisSchemaVersion
    Destination: AnalyticsExportDestination
class StorageClassAnalysis(TypedDict, total=False):
    DataExport: Optional[StorageClassAnalysisDataExport]
class AnalyticsFilter(TypedDict, total=False):