Release support for python 3.14

[nghilethanh09052000]

Summary

Request official support for AWS Lambda python3.14 in docker-lambda: publish ghcr.io/lambgeo/lambda-gdal:{tag}-python3.14 (and related CI/docs) so users can build GDAL-based Lambda packages on the same pattern as existing Python runtimes.

Background

• AWS Lambda added the python3.14 managed runtime (see AWS Lambda runtimes).
• The public.ecr.aws/lambda/python:3.14 image is Amazon Linux 2023 (AL2023), not AL2:
  • Package manager is dnf, not yum.
  • Pre-installed curl-minimal conflicts with installing the full curl package via dnf.

Desired outcome

• Runtime Dockerfile / build args for python3.14 (e.g. RUNTIME_VERSION=3.14).
• CI builds and publishes lambda-gdal:3.8-python3.14 (or current GDAL tag).
• deploy.py / layer metadata includes python3.14 in CompatibleRuntimes where applicable.

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