[pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/adamchainz/blacken-docs: 1.19.0 → 1.19.1](adamchainz/blacken-docs@1.19.0...1.19.1)

Author: pre-commit-ci[bot]

.pre-commit-config.yaml

@@ -38,7 +38,7 @@ repos:
     hooks:
     - id: black
   - repo: https://github.com/adamchainz/blacken-docs
-    rev: "1.19.0"
+    rev: "1.19.1"
     hooks:
     - id: blacken-docs
       args: [--line-length=79]