build(deps): bump linuxserver/nginx from 1.26.2 to 1.26.3

Bumps [linuxserver/nginx](https://github.com/linuxserver/docker-nginx) from 1.26.2 to 1.26.3.
- [Release notes](https://github.com/linuxserver/docker-nginx/releases)
- [Commits](https://github.com/linuxserver/docker-nginx/compare/1.26.2-r0-ls286...1.26.3-r0-ls312

)

---
updated-dependencies:
- dependency-name: linuxserver/nginx
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>