Object Store with IRSA not working

I have applied the following configuration to my cluster in order to enable WAL archiving.
My Object storage is S3, CNPG is running in EKS, and I want to configure access via IRSA.

Cluster:
```
apiVersion: postgresql.cnpg.io/v1
kind: Cluster
spec:
serviceAccountTemplate:
metadata:
annotations:
eks.amazonaws.com/role-arn: arn:aws:iam::
plugins:
- name: barman-cloud.cloudnative-pg.io
isWALArchiver: true
parameters:
barmanObjectName: objectstore
```

ObjectStore:
```
apiVersion: barmancloud.cnpg.io/v1
kind: ObjectStore
metadata:
name: objectstore
spec:
configuration:
data:
compression: bzip2
destinationPath: s3:///
wal:
compression: bzip2
maxParallel: 16
```

Policy attached to SA:
```
{
Action: [
"s3:PutObject",
"s3:GetObject",
"s3:ListBucket",
"s3:DeleteObject",
],
Effect: "Allow",
Resource: [
"arn:aws:s3:::",
"arn:aws:s3:::/*",
],
},
```

However, the WAL archiving is not working with the following error, complaining about missing Azure credentials even though my Object Storage is hosted by AWS.

```
{"level":"error","ts":"2025-08-13T17:06:02.383971021Z","logger":"wal-archive","msg":"Error while calling ArchiveWAL, failing","pluginName":"barman-cloud.cloudnative-pg.io","logging_pod":"metabase-database-3","error":"rpc error: code = Unknown desc = missing Azure credentials","stacktrace":"github.com/cloudnative-pg/machinery/pkg/log.(*logger).Error\n\tpkg/mod/github.com/cloudnative-pg/machinery@v0.3.0/pkg/log/log.go:125\ngithub.com/cloudnative-pg/cloudnative-pg/internal/cnpi/plugin/client.(*data).ArchiveWAL\n\tinternal/cnpi/plugin/client/wal.go:69\ngithub.com/cloudnative-pg/cloudnative-pg/pkg/management/postgres/archiver.archiveWALViaPlugins\n\tpkg/management/postgres/archiver/archiver.go:295\ngithub.com/cloudnative-pg/cloudnative-pg/pkg/management/postgres/archiver.internalRun\n\tpkg/management/postgres/archiver/archiver.go:156\ngithub.com/cloudnative-pg/cloudnative-pg/pkg/management/postgres/archiver.Run\n\tpkg/management/postgres/archiver/archiver.go:141\ngithub.com/cloudnative-pg/cloudnative-pg/internal/cmd/manager/walarchive.NewCmd.func1\n\tinternal/cmd/manager/walarchive/cmd.go:65\ngithub.com/spf13/cobra.(*Command).execute\n\tpkg/mod/github.com/spf13/cobra@v1.9.1/command.go:1015\ngithub.com/spf13/cobra.(*Command).ExecuteC\n\tpkg/mod/github.com/spf13/cobra@v1.9.1/command.go:1148\ngithub.com/spf13/cobra.(*Command).Execute\n\tpkg/mod/github.com/spf13/cobra@v1.9.1/command.go:1071\nmain.main\n\tcmd/manager/main.go:71\nruntime.main\n\t/opt/hostedtoolcache/go/1.24.5/x64/src/runtime/proc.go:283"}
```

Versions:
CNPG 1.26.1
Barman Cloud Plugin 0.5.0

Commencez par suivre le chemin d’archivage WAL à travers internal/cnpi/plugin/client/wal.go et pkg/management/postgres/archiver/archiver.go, en utilisant la configuration signalée de CNPG 1.26.1 et Barman Cloud Plugin 0.5.0 comme contexte de reproduction. Déterminez pourquoi cette configuration AWS S3 demande des identifiants Azure, puis vérifiez le comportement avec un test approprié du plugin ou un test d’intégration ; la tâche est terminée lorsque l’archivage WAL fonctionne via IRSA sans l’erreur d’identifiants Azure.

Rédigé par le modèle d'indexation à partir du texte de l'issue.