minio: add missing region on client initialization (#26412)

The MinIO client isn't redirecting to the correct AWS endpoint if a
non-default data center is used.

In my use case I created an AWS bucket at `eu-central-1` region. Because
of the missing region initialization of the client the default
`us-east-1` API endpoint is used returning a `301 Moved Permanently`
response that's not handled properly by MinIO client. This in return
aborts using S3 storage on AWS as the `BucketExists()` call will fail
with the http moved error.

MinIO client trace shows the issue:

```text
---------START-HTTP---------
HEAD / HTTP/1.1
Host: xxxxxxxxxxx-prod-gitea-data.s3.dualstack.us-east-1.amazonaws.com
User-Agent: MinIO (windows; amd64) minio-go/v7.0.61
Authorization: AWS4-HMAC-SHA256 Credential=**REDACTED**/20230809/accesspoint.eu-central-1/s3/aws4_request, SignedHeaders=host;x-amz-content-sha256;x-amz-date, Signature=**REDACTED**
X-Amz-Content-Sha256: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
X-Amz-Date: 20230809T141143Z

HTTP/1.1 301 Moved Permanently
Connection: close
Content-Type: application/xml
Date: Wed, 09 Aug 2023 14:11:43 GMT
Server: AmazonS3
X-Amz-Bucket-Region: eu-central-1
X-Amz-Id-2: UK7wfeYi0HcTcytNvQ3wTAZ5ZP1mOSMnvRZ9Fz4xXzeNsS47NB/KfFx2unFxo3L7XckHpMNPPVo=
X-Amz-Request-Id: S1V2MJV8SZ11GEVN
---------END-HTTP---------
```

Co-authored-by: Heiko Besemann <heiko.besemann@qbeyond.de>

modules/storage/minio.go

@@ -84,6 +84,7 @@ func NewMinioStorage(ctx context.Context, cfg *setting.Storage) (ObjectStorage,
 		Creds:     credentials.NewStaticV4(config.AccessKeyID, config.SecretAccessKey, ""),
 		Secure:    config.UseSSL,
 		Transport: &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: config.InsecureSkipVerify}},
+		Region:    config.Location,
 	})
 	if err != nil {
 		return nil, convertMinioErr(err)