Update deprecation message, fixes #15645. (#15663)

Author: cpojer

packages/jest-config/src/Deprecated.ts

@@ -89,7 +89,7 @@ const deprecatedOptions: DeprecatedOptions = {
 
   testPathPattern: () =>
     formatDeprecation(
-      'Option *testPathPattern* was replaced by *testPathPatterns*.',
+      'Option *testPathPattern* was replaced by *--testPathPatterns*. *--testPathPatterns* is only available as a command-line option.',
     ),
 
   testURL: (_options: {testURL?: string}) => `  Option ${chalk.bold(