remove unnecessary usages of ThemeProvider

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

plugins/home/src/homePageComponents/HeaderWorldClock/HeaderWorldClock.test.tsx

@@ -17,8 +17,6 @@
 import { renderInTestApp } from '@backstage/test-utils';
 import { HeaderWorldClock, ClockConfig } from './HeaderWorldClock';
 import React from 'react';
-import { lightTheme } from '@backstage/theme';
-import { ThemeProvider } from '@material-ui/core';
 
 describe('HeaderWorldClock with valid Time Zones', () => {
   it('displays Time Zones as expected', async () => {
@@ -42,9 +40,7 @@ describe('HeaderWorldClock with valid Time Zones', () => {
     ];
 
     const rendered = await renderInTestApp(
-      <ThemeProvider theme={lightTheme}>
-        <HeaderWorldClock clockConfigs={clockConfigs} />
-      </ThemeProvider>,
+      <HeaderWorldClock clockConfigs={clockConfigs} />,
     );
 
     expect(rendered.getByText('NYC')).toBeInTheDocument();
@@ -59,9 +55,7 @@ describe('HeaderWorldClock with no Time Zones provided', () => {
     const clockConfigs: ClockConfig[] = [];
 
     const rendered = await renderInTestApp(
-      <ThemeProvider theme={lightTheme}>
-        <HeaderWorldClock clockConfigs={clockConfigs} />
-      </ThemeProvider>,
+      <HeaderWorldClock clockConfigs={clockConfigs} />,
     );
 
     expect(rendered.container).toBeEmptyDOMElement();
@@ -78,9 +72,7 @@ describe('HeaderWorldClock with invalid Time Zone', () => {
     ];
 
     const rendered = await renderInTestApp(
-      <ThemeProvider theme={lightTheme}>
-        <HeaderWorldClock clockConfigs={clockConfigs} />
-      </ThemeProvider>,
+      <HeaderWorldClock clockConfigs={clockConfigs} />,
     );
 
     expect(rendered.getByText('GMT')).toBeInTheDocument();
@@ -105,12 +97,10 @@ describe('HeaderWorldClock with custom Time Format', () => {
     };
 
     const rendered = await renderInTestApp(
-      <ThemeProvider theme={lightTheme}>
-        <HeaderWorldClock
-          clockConfigs={clockConfigs}
-          customTimeFormat={timeFormat}
-        />
-      </ThemeProvider>,
+      <HeaderWorldClock
+        clockConfigs={clockConfigs}
+        customTimeFormat={timeFormat}
+      />,
     );
 
     expect(rendered.getByText('09:10')).toBeInTheDocument();