Revert tox.ini changes

Author: DylanRussell

tox.ini

@@ -153,7 +153,7 @@ deps =
   getting-started: {env:CONTRIB_REPO}\#egg=opentelemetry-instrumentation-wsgi&subdirectory=instrumentation/opentelemetry-instrumentation-wsgi
   getting-started: {env:CONTRIB_REPO}\#egg=opentelemetry-instrumentation-flask&subdirectory=instrumentation/opentelemetry-instrumentation-flask
 
-allowlist_externals = sh, pytest
+allowlist_externals = sh
 
 setenv =
   ; override CONTRIB_REPO_SHA via env variable when testing other branches/commits than main