fix: TypeScript performance of BarPercent.tsx (#11076)

* use correct prop type

* add changeset

---------

Co-authored-by: Banks Nussman <banks@nussman.us>

packages/manager/.changeset/pr-11076-tech-stories-1728498604542.md

@@ -0,0 +1,5 @@
+---
+"@linode/manager": Tech Stories
+---
+
+Fix TypeScript Performance of `BarPercent.tsx` ([#11076](https://github.com/linode/manager/pull/11076))

packages/manager/src/components/BarPercent/BarPercent.tsx

@@ -1,10 +1,11 @@
 import { styled } from '@mui/material/styles';
-import { SxProps } from '@mui/system';
 import * as React from 'react';
 
 import { LinearProgress } from 'src/components/LinearProgress';
 import { omittedProps } from 'src/utilities/omittedProps';
 
+import type { SxProps, Theme } from '@mui/material/styles';
+
 export interface BarPercentProps {
   /** Additional css class to pass to the component */
   className?: string;
@@ -16,7 +17,7 @@ export interface BarPercentProps {
   narrow?: boolean;
   /** Applies a `border-radius` to the bar. */
   rounded?: boolean;
-  sx?: SxProps;
+  sx?: SxProps<Theme>;
   /** The value of the progress indicator for the determinate and buffer variants. */
   value: number;
   /** The value for the buffer variant. */