temporarily exclude pypy-3 from testing as it fails, possibly due to ecs-logging (#1100)

Author: beniwohli

.ci/.jenkins_exclude.yml

@@ -1,4 +1,6 @@
 exclude:
+  - PYTHON_VERSION: pypy-3  # pypy3 currently fails on CI, e.g. https://apm-ci.elastic.co/blue/organizations/jenkins/apm-agent-python%2Fapm-agent-python-mbp/detail/PR-1099/2/pipeline#step-3497-log-1
+    FRAMEWORK: none
   # Flask
   - PYTHON_VERSION: pypy-3
     FRAMEWORK: flask-0.11 # see https://github.com/pallets/flask/commit/6e46d0cd, 0.11.2 was never released