docs: fix outdated tags, env-vars wording, and copyright year (#636)

Update the README to match the actual build configuration in
.github/workflows/main.yml:

- Replace stale Docker tag list (10.16.2, 10.16.1, 10.15.3) with the
  tags actually built: 10.16.3, 10.16, 10, latest
- Reword "Environment variables: None" to point at the inherited
  base-image variables instead
- Bump copyright year to 2022-2026 in README and LICENSE

Signed-off-by: Thomas Müller <1005065+DeepDiver1975@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: DeepDiver1975

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2022 ownCloud GmbH
+Copyright (c) 2022-2026 ownCloud GmbH
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -29,9 +29,7 @@ ownCloud is an open-source file sync, share and content collaboration software t
 
 ## Docker Tags and respective Dockerfile links
 
-- [`10.16.2`](https://github.com/owncloud-docker/server/blob/master/v22.04/Dockerfile.multiarch) available as `owncloud/server:10.16.2`
-- [`10.16.1`](https://github.com/owncloud-docker/server/blob/master/v22.04/Dockerfile.multiarch) available as `owncloud/server:10.16.1`
-- [`10.15.3`](https://github.com/owncloud-docker/server/blob/master/v22.04/Dockerfile.multiarch) available as `owncloud/server:10.15.3`
+- [`10.16.3`, `10.16`, `10`, `latest`](https://github.com/owncloud-docker/server/blob/master/v22.04/Dockerfile.multiarch) available as `owncloud/server:10.16.3`
 - [`11.0.0-prealpha`](https://github.com/owncloud-docker/server/blob/master/v24.04/Dockerfile.multiarch) available as `owncloud/server:11.0.0-prealpha`
 
 ## Default volumes
@@ -60,7 +58,9 @@ command: ["/usr/bin/owncloud", "occ", "wnd:listen", "myhost", "myshare", "myuser
 
 ## Environment variables
 
-None
+This image defines no environment variables of its own. Configuration is done
+through the variables inherited from the base images linked under
+[Inherited environments](#quick-reference) above.
 
 ## License
 
@@ -69,5 +69,5 @@ This project is licensed under the MIT License - see the [LICENSE](https://githu
 ## Copyright
 
 ```Text
-Copyright (c) 2022 ownCloud GmbH
+Copyright (c) 2022-2026 ownCloud GmbH
 ```