Bump anyio from 3.6.2 to 4.12.1

Bumps [anyio](https://github.com/agronholm/anyio) from 3.6.2 to 4.12.1.
- [Release notes](https://github.com/agronholm/anyio/releases)
- [Commits](agronholm/anyio@3.6.2...4.12.1)

---
updated-dependencies:
- dependency-name: anyio
  dependency-version: 4.12.1
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

backend/requirements.txt

@@ -1,6 +1,6 @@
-anyio==3.6.2 ; python_version >= "3.8" and python_version < "4.0" \
-    --hash=sha256:25ea0d673ae30af41a0c442f81cf3b38c7e79fdc7b60335a4c14e05eb0947421 \
-    --hash=sha256:fbbe32bd270d2a2ef3ed1c5d45041250284e31fc0a4df4a5a6071842051a51e3
+anyio==4.12.1 ; python_version >= "3.8" and python_version < "4.0" \
+    --hash=sha256:41cfcc3a4c85d3f05c932da7c26d0201ac36f72abd4435ba90d0464a3ffed703 \
+    --hash=sha256:d405828884fc140aa80a3c667b8beed277f1dfedec42ba031bd6ac3db606ab6c
 cfgv==3.3.1 ; python_version >= "3.8" and python_version < "4.0" \
     --hash=sha256:c6a0883f3917a037485059700b9e75da2464e6c27051014ad85ba6aaa5884426 \
     --hash=sha256:f5a830efb9ce7a445376bb66ec94c638a9787422f96264c98edc6bdeed8ab736