Update anyio requirement from ~=3.7.1 to ~=4.3.0

Updates the requirements on [anyio](https://github.com/agronholm/anyio) to permit the latest version.
- [Release notes](https://github.com/agronholm/anyio/releases)
- [Changelog](https://github.com/agronholm/anyio/blob/master/docs/versionhistory.rst)
- [Commits](agronholm/anyio@3.7.1...4.3.0)

---
updated-dependencies:
- dependency-name: anyio
  dependency-type: direct:production
...

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

requirements.txt

@@ -1,5 +1,5 @@
 aiolimiter~=1.1.0
-anyio~=3.7.1
+anyio~=4.3.0
 apngasm_python~=1.2.3
 av~=12.0.0
 beautifulsoup4~=4.12.3