update test to conform to new jest library

Author: pavera

__tests__/image-service.test.ts

@@ -8,10 +8,8 @@ jest.mock('@actions/core')
 describe('ImageService', () => {
   describe('when asked to fetch non-GitHub hosted images', () => {
     test('it raises an error', async () => {
-      await expect(ImageService.pull('hello-world')).rejects.toThrowError(
-        new Error(
-          'Only images distributed via docker.pkg.github.com or ghcr.io can be fetched'
-        )
+      await expect(ImageService.pull('hello-world')).rejects.toThrow(
+        'Only images distributed via docker.pkg.github.com or ghcr.io can be fetched'
       )
     })
   })