Remove CVE-2026-82049 exception after fixed Python 3.13 release #12

Temporarily accept CVE-2026-82049 for the python binary package at exactly version 3.13.15 so image builds can pass the Grype gate while waiting for a fixed upstream Python 3.13 release. This exception does not remediate the tarfile extraction vulnerability.

The Python 3.13 backport was merged after 3.13.15.

Once a fixed official Python 3.13 Alpine image is available:

• Upgrade the configured Python 3.13 version and verify it contains the upstream fix.
• Remove the CVE-2026-82049 exception from .grype.yaml.
• Build and test supported variants on amd64 and arm64, and verify Grype passes without the exception.