chore(deps): update python docker tag to v3.9.5 (#1069)

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This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| python | final | minor | `3.8.9-buster` -> `3.9.5-buster` |
| python | final | patch | `3.9.4-buster` -> `3.9.5-buster` |

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docker/owlbot/nodejs/Dockerfile

@@ -16,7 +16,7 @@
 
 # build from the root of this repo:
 # docker build -t gcr.io/repo-automation-bots/owlbot-nodejs -f docker/owlbot/nodejs/Dockerfile .
-FROM python:3.9.4-buster
+FROM python:3.9.5-buster
 
 WORKDIR /
 

docker/owlbot/python/Dockerfile

@@ -16,7 +16,7 @@
 
 # build from the root of this repo:
 # docker build -t gcr.io/repo-automation-bots/owlbot-python -f docker/owlbot/python/Dockerfile .
-FROM python:3.8.9-buster
+FROM python:3.9.5-buster
 
 WORKDIR /