build(deps): bump matrix-sdk from 0.17.0 to 0.18.0

Bumps [matrix-sdk](https://github.com/matrix-org/matrix-rust-sdk) from 0.17.0 to 0.18.0.
- [Release notes](https://github.com/matrix-org/matrix-rust-sdk/releases)
- [Changelog](https://github.com/matrix-org/matrix-rust-sdk/blob/main/release.toml)
- [Commits](matrix-org/matrix-rust-sdk@matrix-sdk-0.17.0...matrix-sdk-0.18.0)

---
updated-dependencies:
- dependency-name: matrix-sdk
  dependency-version: 0.18.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]