Ddtrace now requires patch.py rather than __init__.py files. (#566)

Author: purple4reina

Diff for: Dockerfile

@@ -47,10 +47,10 @@ RUN rm -rf \
 # https://docs.python.org/3.11/using/cmdline.html#cmdoption-O
 # https://docs.python.org/3/using/cmdline.html#envvar-PYTHONNODEBUGRANGES
 RUN PYTHONNODEBUGRANGES=1 python -OO -m compileall -b ./python/lib/$runtime/site-packages
-# remove all .py files except ddtrace/contrib/*/__init__.py which are necessary
+# remove all .py files except ddtrace/contrib/*/patch.py which are necessary
 # for ddtrace.patch to discover instrumationation packages.
 RUN find ./python/lib/$runtime/site-packages -name \*.py | grep -v ddtrace/contrib | xargs rm -rf
-RUN find ./python/lib/$runtime/site-packages/ddtrace/contrib -name \*.py | grep -v __init__ | xargs rm -rf
+RUN find ./python/lib/$runtime/site-packages/ddtrace/contrib -name \*.py | grep -v patch.py | xargs rm -rf
 RUN find ./python/lib/$runtime/site-packages -name __pycache__ -type d -exec rm -r {} \+
 
 # When building ddtrace from branch, remove extra source files.  These are