Revert "Add testing hints (#39868)" (#39921)

Revert "Add testing hints"
diff --git a/testing/README.md b/testing/README.md
deleted file mode 100644
index f3c65cd..0000000
--- a/testing/README.md
+++ /dev/null
@@ -1,18 +0,0 @@
-# Engine Testing
-
-This directory contains the infrastructure for running tests on the engine,
-which are most often run by Flutter's continuous integration (CI) systems.
-
-The tests themselves are located in other directories, closer to the source for
-each platform, language, and variant. For instance, macOS engine unit tests
-written in objective C are located in the same directory as the source files,
-but with a `Test` suffix added (e.g. "FlutterEngineTest.mm" holds the tests for
-"FlutterEngine.mm", and they are located in the same directory).
-
-## Testing the Engine locally
-
-If you are working on the engine, you will want to be able to run tests locally.
-
-In order to learn the details of how do that, please consult the [Flutter Wiki
-page](https://github.com/flutter/flutter/wiki/Testing-the-engine) on the
-subject.
diff --git a/testing/run_tests.py b/testing/run_tests.py
index 37f9389..0eed650 100755
--- a/testing/run_tests.py
+++ b/testing/run_tests.py
@@ -947,12 +947,7 @@
 
 
 def main():
-  parser = argparse.ArgumentParser(
-      description='''
-In order to learn the details of running tests in the engine, please consult the
-Flutter Wiki page on the subject: https://github.com/flutter/flutter/wiki/Testing-the-engine
-'''
-  )
+  parser = argparse.ArgumentParser()
   all_types = [
       'engine', 'dart', 'benchmarks', 'java', 'android', 'objc', 'font-subset'
   ]