refactor(docker): add rosdistro-suffixed tag aliases for uniform image naming

[xmfcx]

Summary

Add latest-humble and cuda-latest-humble tag aliases to the autoware-base Docker images so that all distros follow a uniform latest-{rosdistro} / cuda-latest-{rosdistro} naming convention.

This would allow load-env.yaml to derive image names via simple string interpolation instead of a case statement, and make adding future distros zero-touch in CI.

Context

• Suggested by @youtalk in refactor(ci): pass rosdistro instead of env files to workflows #6952 (comment):
  refactor(ci): pass rosdistro instead of env files to workflows #6952 (comment)

Currently humble uses bare :latest / :cuda-latest tags while jazzy uses :latest-jazzy / :cuda-latest-jazzy. Unifying the scheme removes the need for per-distro branching in load-env.yaml.

Tasks

• Publish additional latest-humble and cuda-latest-humble tags in docker-build-and-push.yaml
• Simplify load-env.yaml case statement to use latest-${rosdistro} interpolation
• Keep bare :latest / :cuda-latest as aliases for backwards compatibility

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• Parent issue: refactor(ansible): move version pins from .env files to ansible role defaults #6938