style: format code with Go fmt and Gofumpt

This commit fixes the style issues introduced in 652e8c9 according to the output
from Go fmt and Gofumpt.

Details: #1

Author: deepsource-autofix[bot]

lura/attributes.go

@@ -29,7 +29,6 @@ import (
 //   - backend-request: when reporting the request to the backends
 //   - server address: the host for the request
 func backendConfigAttributes(cfg *config.Backend, stage string) []attribute.KeyValue {
-
 	urlPattern := kotelconfig.NormalizeURLPattern(cfg.URLPattern)
 	parentEndpoint := kotelconfig.NormalizeURLPattern(cfg.ParentEndpoint)