Not all versions returned in `available_releases` have a corresponding binary

**Describe the bug**
For aarch64+mac (mac m2 devices), there is no release of feature version 8, which results in an inconsistency between the binary api and the available_releases api

Maybe add some filters to the `available_releases` api?

**To Reproduce**
Steps to reproduce the behavior:
1. Fetch the available releases from the `available_releases` api
2. Use the version 8 returned to construct a new request for binary
3. Make the request
4. Get the 404 error

**Expected behavior**
Either build the version or add filters to the available releases api

**Device (please complete the following information):**
- OS: MacOS

Start by reproducing the available_releases and binary API requests for aarch64 macOS feature version 8 and compare their results. Trace how each endpoint determines available releases, then confirm that every returned version has a corresponding binary or is filtered out when unavailable.

Written by the indexing model from the issue text.