tf-github-autoresponse.yaml: fix error while installing pygithub package

Add '--break-system-packages' pip argument

Signed-off-by: Arthur She <arthur.she@linaro.org>
Change-Id: Icc4c078b6e8b3e3da5d18ce40486d4d369689404
diff --git a/ci/run_github_autoreply.sh b/ci/run_github_autoreply.sh
index dc94c76..12f9fa9 100755
--- a/ci/run_github_autoreply.sh
+++ b/ci/run_github_autoreply.sh
@@ -9,7 +9,7 @@
 python3 -c "import github"
 if [ $? != 0 ]
 then
-	yes | pip3 install pygithub
+	yes | pip3 install pygithub --break-system-packages
 fi
 
 # Run bot