fix: enable sharedConfigState in AWS auth provider (#2777)

The value `session.SharedConfigDisable` prevented the AWS SDK to use the
default provider chain. By removing this value from the getAWSSession
function the default SDK provider chain is used. This enables the SDK to
use the shared config file:
https://github.com/aws/aws-sdk-go/blob/main/aws/session/env_config.go#L84
as well as the shared credentials file:
https://github.com/aws/aws-sdk-go/blob/main/aws/session/env_config.go#L76

This fixes the code to be correct with the documentation of
NewGeneratorSession which notes that it uses the authentication order:

1. service-account token.
2. static credentials.
3. sdk default provider.

See also the AWS documentation:
https://github.com/aws/aws-sdk-go/blob/main/aws/session/session.go#L158

Signed-off-by: Kevin van den Broek <info@kevinvandenbroek.nl>

pkg/provider/aws/auth/auth.go

@@ -373,9 +373,8 @@ func getAWSSession(config *aws.Config, enableCache bool, name, kind, namespace,
 	handlers := defaults.Handlers()
 	handlers.Build.PushBack(request.WithAppendUserAgent("external-secrets"))
 	sess, err := session.NewSessionWithOptions(session.Options{
-		Config:            *config,
-		Handlers:          handlers,
-		SharedConfigState: session.SharedConfigDisable,
+		Config:   *config,
+		Handlers: handlers,
 	})
 	if err != nil {
 		return nil, err