Bump starlette in /requirements in the pip group across 1 directory

Bumps the pip group with 1 update in the /requirements directory: [starlette](https://github.com/encode/starlette).


Updates `starlette` from 0.38.2 to 0.40.0
- [Release notes](https://github.com/encode/starlette/releases)
- [Changelog](https://github.com/encode/starlette/blob/master/docs/release-notes.md)
- [Commits](encode/starlette@0.38.2...0.40.0)

---
updated-dependencies:
- dependency-name: starlette
  dependency-type: direct:production
  dependency-group: pip
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements/requirements-ci.lock.txt

@@ -307,7 +307,7 @@ sqlparse==0.5.1
     # via
     #   -r requirements/requirements-test.lock.txt
     #   django
-starlette==0.38.2
+starlette==0.40.0
     # via sphinx-autobuild
 stevedore==5.3.0
     # via doc8

requirements/requirements-dev.lock.txt

@@ -431,7 +431,7 @@ sqlparse==0.5.1
     #   django
 stack-data==0.6.3
     # via ipython
-starlette==0.38.2
+starlette==0.40.0
     # via
     #   -r requirements/requirements-ci.lock.txt
     #   sphinx-autobuild