lib/backup/s3remote: add retryer configuration (#6747)

### Describe Your Changes

This helps to improve reliability of performing backups in environments
with unreliable connection and tolerate temporary errors at S3 provider
side.

See: https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6732

Default retry timeout is up to 3 minutes to make this consistent with
the same configuration for GCS:
a05317f61f/lib/backup/gcsremote/gcs.go (L70-L76)

### Checklist

The following checks are **mandatory**:

- [x] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).

---------

Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>

docs/CHANGELOG.md

@@ -33,6 +33,7 @@ See also [LTS releases](https://docs.victoriametrics.com/lts-releases/).
 * FEATURE: [vmctl](https://docs.victoriametrics.com/vmctl/): add `--vm-backoff-retries`, `--vm-backoff-factor`, `--vm-backoff-min-duration` and `--vm-native-backoff-retries`, `--vm-native-backoff-factor`, `--vm-native-backoff-min-duration` command-line flags. These flags allow to change backoff policy config for import requests to VictoriaMetrics. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6622).
 * FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent/): allow overriding the `sample_limit` option at [scrape_configs](https://docs.victoriametrics.com/sd_configs/#scrape_configs) when a label `__sample_limit__` is specified for target. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6665). Thanks to @zoglam for the [pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6666).
 * FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent/): reduce memory usage when scraping targets with big response body. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6759).
+* FEATURE: [vmbackup](https://docs.victoriametrics.com/vmbackup/), [vmrestore](https://docs.victoriametrics.com/vmrestore/), [vmbackupmanager](https://docs.victoriametrics.com/vmbackupmanager/): use exponential backoff for retries when uploading or downloading data from S3. This should reduce the number of failed uploads and downloads when S3 is temporarily unavailable. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6732).
 
 * BUGFIX: [vmalert](https://docs.victoriametrics.com/vmalert): respect HTTP headers defined in [notifier configuration file](https://docs.victoriametrics.com/vmalert/#notifier-configuration-file) for each request to notifiers. Previously, this param was ignored by mistake.
 * BUGFIX: [stream aggregation](https://docs.victoriametrics.com/stream-aggregation/): correctly apply `-streamAggr.dropInputLabels` when global stream deduplication is enabled without `-streamAggr.config`. Previously, `-remoteWrite.streamAggr.dropInputLabels` was used instead.

lib/backup/s3remote/s3.go

@@ -9,8 +9,10 @@ import (
 	"net/http"
 	"path"
 	"strings"
+	"time"
 
 	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/aws/retry"
 	"github.com/aws/aws-sdk-go-v2/config"
 	"github.com/aws/aws-sdk-go-v2/feature/s3/manager"
 	"github.com/aws/aws-sdk-go-v2/service/s3"
@@ -97,6 +99,12 @@ func (fs *FS) Init() error {
 	configOpts := []func(*config.LoadOptions) error{
 		config.WithSharedConfigProfile(fs.ProfileName),
 		config.WithDefaultRegion("us-east-1"),
+		config.WithRetryer(func() aws.Retryer {
+			return retry.NewStandard(func(o *retry.StandardOptions) {
+				o.Backoff = retry.NewExponentialJitterBackoff(3 * time.Minute)
+				o.MaxAttempts = 10
+			})
+		}),
 	}
 
 	if len(fs.ConfigFilePath) > 0 {