fix: Read "404" as object not exist (#13901)

**What this PR does / why we need it**:
Modify the s3 client to recognize "NotFound" errors when checking if an object error is "NotFound".
I did some tests locally and `Head` calls to objects that doesn't exist gives a "NotFound" instead of "NoSuchKey".

pkg/storage/chunk/client/aws/s3_storage_client.go

@@ -501,7 +501,13 @@ func (a *S3ObjectClient) List(ctx context.Context, prefix, delimiter string) ([]
 
 // IsObjectNotFoundErr returns true if error means that object is not found. Relevant to GetObject and DeleteObject operations.
 func (a *S3ObjectClient) IsObjectNotFoundErr(err error) bool {
-	if aerr, ok := errors.Cause(err).(awserr.Error); ok && aerr.Code() == s3.ErrCodeNoSuchKey {
+	aerr, ok := errors.Cause(err).(awserr.Error)
+	if !ok {
+		return false
+	}
+
+	code := aerr.Code()
+	if code == s3.ErrCodeNoSuchKey || code == "NotFound" {
 		return true
 	}
 

pkg/storage/chunk/client/aws/s3_storage_client_test.go

@@ -23,6 +23,7 @@ import (
 	"github.com/grafana/loki/v3/pkg/storage/chunk/client/hedging"
 
 	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/awserr"
 	"github.com/aws/aws-sdk-go/aws/request"
 	"github.com/aws/aws-sdk-go/service/s3"
 	"github.com/aws/aws-sdk-go/service/s3/s3iface"
@@ -34,6 +35,44 @@ func (f RoundTripperFunc) RoundTrip(req *http.Request) (*http.Response, error) {
 	return f(req)
 }
 
+func TestIsObjectNotFoundErr(t *testing.T) {
+	tests := []struct {
+		err      error
+		expected bool
+		name     string
+	}{
+		{
+			name:     "no such key error is recognized as object not found",
+			err:      awserr.New(s3.ErrCodeNoSuchKey, "NoSuchKey", nil),
+			expected: true,
+		},
+		{
+			name:     "NotFound code is recognized as object not found",
+			err:      awserr.New("NotFound", "NotFound", nil),
+			expected: true,
+		},
+		{
+			name:     "Nil error isnt recognized as object not found",
+			err:      nil,
+			expected: false,
+		},
+		{
+			name:     "Other error isnt recognized as object not found",
+			err:      awserr.New(s3.ErrCodeNoSuchBucket, "NoSuchBucket", nil),
+			expected: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			client, err := NewS3ObjectClient(S3Config{BucketNames: "mybucket"}, hedging.Config{})
+			require.NoError(t, err)
+
+			require.Equal(t, tt.expected, client.IsObjectNotFoundErr(tt.err))
+		})
+	}
+}
+
 func TestRequestMiddleware(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		fmt.Fprintln(w, r.Header.Get("echo-me"))