fix: remove duplicate python installation

[mchekalov]

What type of PR is this? (check all applicable)

• Refactor
• Feature
• Bug Fix
• Optimization
• Documentation Update

Description

There are two pythons are installed in Dockerfile:
/usr/local/bin/python3 → python3.13 (comes from base image)
/usr/bin/python3 → python3.12 (installed with apk add py3-yaml, not used)
After removing duplicate image size is smaller, fewer problems when updating or handling

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Breaking Change checklist

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