Hubble Soars to New Heights with Major Update: v1.15.6 Released!

The latest iteration introduces vital enhancements including gRPC server metrics and optimizations for message bundle sizes, setting the stage for unparalleled performance!

Commit Details:

chore: release hubble v1.15.6 (#2359) Releasing hubble v1.15.6 ## Merge Checklist _Choose all relevant options below by adding an `x` now or at any time before submitting for review_ - [x] PR title adheres to the [conventional commits](https://www.conventionalcommits.org/en/v1.0.0/) standard - [x] PR has a [changeset](https://github.com/farcasterxyz/hub-monorepo/blob/main/CONTRIBUTING.md#35-adding-changesets) - [x] PR has been tagged with a change label(s) (i.e. documentation, feature, bugfix, or chore) - [ ] PR includes [documentation](https://github.com/farcasterxyz/hub-monorepo/blob/main/CONTRIBUTING.md#32-writing-docs) if necessary. <!-- start pr-codex --> --- ## PR-Codex overview This PR primarily focuses on updating the version of the `@farcaster/hubble` package from `1.15.5` to `1.15.6`. It includes updates to the `CHANGELOG.md` to reflect the new version and its associated changes. ### Detailed summary - Updated `version` of `@farcaster/hubble` from `1.15.5` to `1.15.6` in `package.json`. - Added a new section for version `1.15.6` in `CHANGELOG.md`: - `c2c409fb`: Added metrics for gRPC server. - `1ca66d8c`: Fixed limit on message bundle size. > ✨ Ask PR-Codex anything about this PR by commenting with `/codex {your question}` <!-- end pr-codex -->