Doc: Remove deleted link (#5338)

The linked file was deleted in #5241.

airbyte-integrations/bases/standard-source-test/readme.md

@@ -30,4 +30,4 @@ Check out each function in [SourceAcceptanceTest](src/main/java/io/airbyte/integ
 ## Do I have to write java to use these tests?
 No! Our goal is to allow you to write your integration _entirely_ in your language of choice. If you are writing an integration in Python, for instance, you should be able to interact with this test suite in python and not need to write java. _Right now, we only have a Python interface to reduce friction for interacting with these tests_, and with time, we intend to make more language-specific helpers available. In the meantime, however, you can still use your language of choice and leverage this standard test suite. 
 
-If working in Python, the Python interface that you need to implement can be found [here](../base-python-test/base_python_test/test_iface.py). Our [python template](../../connector-templates/source-python/README.md.hbs) and [singer template](../../connector-templates/source-singer/README.md.hbs) also walk you through how to implement the interface. You can also find an example of how this is done for an already existing integration [here](../../connectors/source-github-singer/integration_tests/integration_source_test.py).
+If working in Python, the Python interface that you need to implement can be found [here](../base-python-test/base_python_test/test_iface.py). Our [python template](../../connector-templates/source-python/README.md.hbs) and [singer template](../../connector-templates/source-singer/README.md.hbs) also walk you through how to implement the interface.