[pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/asottile/blacken-docs: 1.19.1 → 1.20.0](adamchainz/blacken-docs@1.19.1...1.20.0)

Author: pre-commit-ci[bot]

.pre-commit-config.yaml

@@ -25,7 +25,7 @@ repos:
         args: [--safe, --quiet]
         language_version: python3
 -   repo: https://github.com/asottile/blacken-docs
-    rev: 1.19.1
+    rev: 1.20.0
     hooks:
     -   id: blacken-docs
         additional_dependencies: [black==23.1.0]