Chore: Fix issues reported by staticcheck; enable stylecheck linter (#28866)

* Chore: Fix issues reported by staticcheck

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Apply suggestions from code review

Co-authored-by: Emil Tullstedt <emil.tullstedt@grafana.com>

pkg/api/plugins.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
+
 	"github.com/grafana/grafana/pkg/api/dtos"
 	"github.com/grafana/grafana/pkg/bus"
 	"github.com/grafana/grafana/pkg/models"