chore(deps): bump diesel from 2.2.7 to 2.2.8 in /examples (#560)

Bumps [diesel](https://github.com/diesel-rs/diesel) from 2.2.7 to 2.2.8.
- [Release notes](https://github.com/diesel-rs/diesel/releases)
- [Changelog](https://github.com/diesel-rs/diesel/blob/v2.2.8/CHANGELOG.md)
- [Commits](https://github.com/diesel-rs/diesel/compare/v2.2.7...v2.2.8)

---
updated-dependencies:
- dependency-name: diesel
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

examples/Cargo.lock

@@ -863,9 +863,9 @@ dependencies = [
 
 [[package]]
 name = "diesel"
-version = "2.2.7"
+version = "2.2.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "04001f23ba8843dc315804fa324000376084dfb1c30794ff68dd279e6e5696d5"
+checksum = "470eb10efc8646313634c99bb1593f402a6434cbd86e266770c6e39219adb86a"
 dependencies = [
  "diesel_derives",
  "libsqlite3-sys",