Fix Python/uvicorn start/stop issues (#7221)

frameworks/Python/uvicorn/requirements.txt

@@ -1,6 +1,6 @@
 asyncpg==0.21.0
 gunicorn==20.0.4
-Jinja2==2.11.3
+Jinja2==3.0.3
 ujson==2.0.3
 uvloop==0.14.0
 uvicorn==0.11.7