update copyright year (#24088)

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## Description

Updated year to 2026

## Related issues or tickets

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## Reviews

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- [ ] Editorial review

Signed-off-by: Craig Osterhout <craig.osterhout@docker.com>

Author: craig-osterhout

README.md

@@ -37,4 +37,4 @@ We welcome contributions! To get started:
 
 ## Copyright and license
 
-Copyright 2013-2025 Docker, Inc., released under the [Apache 2.0 license](https://github.com/docker/docs/blob/main/LICENSE).
+Copyright 2013-2026 Docker, Inc., released under the [Apache 2.0 license](https://github.com/docker/docs/blob/main/LICENSE).