Checkbox: Fix extraneous right hand margin when no label is present (#68885)

* remove explicit grid columns, let it automatically work it out

* restore position: relative;

packages/grafana-ui/src/components/Forms/Checkbox.tsx

@@ -68,8 +68,6 @@ export const getCheckboxStyles = stylesFactory((theme: GrafanaTheme2) => {
       display: inline-grid;
       align-items: center;
       column-gap: ${theme.spacing(labelPadding)};
-      grid-template-columns: auto 1fr;
-      grid-template-rows: auto auto;
       position: relative;
       vertical-align: middle;
     `,