chore(deps): update dependency twilio to v7.8.0 (GoogleCloudPlatform#7626)

Co-authored-by: Leah E. Cole <[email protected]>

Author: renovate-bot

appengine/flexible/twilio/requirements.txt

@@ -1,3 +1,3 @@
 Flask==2.0.2
 gunicorn==20.1.0
-twilio==7.7.1
+twilio==7.8.0