Google no longer serves the `tools` package: it is gone from
repository2-3.xml, so `sdkmanager tools` fails with
"Failed to find package 'tools'" and takes the whole action down with it.
- Drop `tools` from the default value of the `packages` input, leaving
`platform-tools`. The command line tools that replaced it are already
installed by this action, and there is no bare `cmdline-tools` package
path to install instead (only versioned ones, e.g. `cmdline-tools;20.0`).
- Skip `tools` with a warning when it is requested explicitly, so the
many workflows that pass `packages: 'tools platform-tools'` keep working
instead of failing.
- Update the README accordingly.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
