plugins/semanticcache/v1.6.9

## Plugin Release: semanticcache v1.6.9

- fix: scope cache keys per virtual key so a shared cache_key or default_cache_key never serves one virtual key's response to another; the vk: namespace is reserved and per-request threshold overrides are floored at the configured value and capped at 1.0 (#7862)
  <Warning>
  Entries written before the upgrade under a virtual key are not reused, so expect a cold cache. Unscoped cache keys starting with vk: are moved to raw:vk:. A per-request threshold can only raise the configured threshold.
  </Warning>
- chore: upgraded core to v1.11.2 and framework to v1.8.1

### Installation

```bash
# Update your go.mod to use the new plugin version
go get github.com/maximhq/bifrost/plugins/semanticcache@v1.6.9
```

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_This release was automatically created from version file: `plugins/semanticcache/version`_