⬆ Bump starlette from 0.20.4 to 0.21.0

Bumps [starlette](https://github.com/encode/starlette) from 0.20.4 to 0.21.0.
- [Release notes](https://github.com/encode/starlette/releases)
- [Changelog](https://github.com/encode/starlette/blob/master/docs/release-notes.md)
- [Commits](encode/starlette@0.20.4...0.21.0)

---
updated-dependencies:
- dependency-name: starlette
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

pyproject.toml

@@ -38,7 +38,7 @@ classifiers = [
     "Topic :: Internet :: WWW/HTTP",
 ]
 dependencies = [
-    "starlette==0.20.4",
+    "starlette==0.21.0",
     "pydantic >=1.6.2,!=1.7,!=1.7.1,!=1.7.2,!=1.7.3,!=1.8,!=1.8.1,<2.0.0",
 ]
 dynamic = ["version"]