Add canonical NOTICE source and sync hook

[xchwan]

issue: #60540

Summary

Introduces a canonical NOTICE template and a manual prek hook to keep all distribution NOTICE files in sync.

The repo has 170+ NOTICE files maintained independently. When the ASF header needs updating (e.g. wording change, year), every file must be touched manually with no automation to ensure consistency.

Annual year updates are handled by a separate update-notice-year hook.

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Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)
  Claude Code Sonnet 4.6

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• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst, in airflow-core/newsfragments. You can add this file in a follow-up commit after the PR is created so you know the PR number.

[potiuk]

the notice file never changes - it can diverge. There is no point in syncing those, dfferent story with licence headers that are added to files and they are modified independently.