Add more linters to improve code readability (#19989)

Add nakedret, unconvert, wastedassign, stylecheck and nolintlint linters to improve code readability

- nakedret - https://github.com/alexkohler/nakedret - nakedret is a Go static analysis tool to find naked returns in functions greater than a specified function length.
- unconvert - https://github.com/mdempsky/unconvert - Remove unnecessary type conversions
- wastedassign - https://github.com/sanposhiho/wastedassign -  wastedassign finds wasted assignment statements.
- notlintlint -  Reports ill-formed or insufficient nolint directives
- stylecheck - https://staticcheck.io/docs/checks/#ST - keep style consistent
  - excluded: [ST1003 - Poorly chosen identifier](https://staticcheck.io/docs/checks/#ST1003) and [ST1005 - Incorrectly formatted error string](https://staticcheck.io/docs/checks/#ST1005)

models/action.go

@@ -459,7 +459,7 @@ func DeleteOldActions(olderThan time.Duration) (err error) {
 	}
 
 	_, err = db.GetEngine(db.DefaultContext).Where("created_unix < ?", time.Now().Add(-olderThan).Unix()).Delete(&Action{})
-	return
+	return err
 }
 
 func notifyWatchers(ctx context.Context, actions ...*Action) error {