Update Container Version(s)

[www-signal-fyi]

Updating:
python:3.7

[codara-ai-code-review]

Potential issues, bugs, or flaws:

1. /app/Dockerfile:1
   • Docker image tag should not include the digest in the FROM statement. It's sufficient to specify the base image without referencing a specific digest.
   • The line FROM python:3.7@sha256:2011a37d2a08fe83dd9ff923e0f83bfd7290152e2e6afe359bde1453170d9bdc should be reverted to FROM python:3.7

Suggestions, improvements, etc.:

N/A