[Lens] Fix issue where "Elastic UI Numeric" font is applied to portals outside of Lens (elastic#261168)

## Summary

Fix issue where `"Elastic UI Numeric"` font is applied to portals
outside of Lens e.g. fields overview popover in Discover or Datepicker
popover. (The monospaced font `"Elastic UI Numeric"` is added in
elastic#251576)

Before

<img width="1237" height="997" alt="image"
src="https://github.com/user-attachments/assets/0f140778-44fe-4644-ab3d-e19e71507c69"
/>


After

<img width="1239" height="997" alt="image"
src="https://github.com/user-attachments/assets/256f4288-aa7d-4809-b623-bc1cae464c2f"
/>

Author: awahab07

x-pack/platform/plugins/shared/lens/public/expression_renderer_styles.tsx

@@ -40,8 +40,7 @@ export const lnsExpressionRendererStyle = (euiThemeContext: UseEuiTheme) => {
  * These elements are rendered outside the Lens DOM tree and need global targeting.
  */
 export const lnsGlobalChartStyles = (euiThemeContext: UseEuiTheme) => css`
-  [id^='echTooltipPortal'],
-  [data-euiportal='true'] {
+  [id^='echTooltipPortal'] {
     ${lnsNumericFontStyles(euiThemeContext)}
   }
 `;