Bump rack from 3.0.8 to 3.0.9.1 in /examples/streaming_upload

Bumps [rack](https://github.com/rack/rack) from 3.0.8 to 3.0.9.1.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@v3.0.8...v3.0.9.1)

---
updated-dependencies:
- dependency-name: rack
  dependency-type: indirect
...

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

examples/streaming_upload/gems.locked

@@ -59,7 +59,7 @@ GEM
     protocol-rack (0.4.1)
       protocol-http (~> 0.23)
       rack (>= 1.0)
-    rack (3.0.8)
+    rack (3.0.9.1)
     samovar (2.2.0)
       console (~> 1.0)
       mapping (~> 1.0)