Consistent versions in pre-comit config file

Follow the style of the pre-commit doc itself:
https://pre-commit.com/#2-add-a-pre-commit-configuration

Author: DimitriPapadopoulos

.pre-commit-config.yaml

@@ -1,14 +1,14 @@
 repos:
   - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: "v1.11.2"
+    rev: v1.11.2
     hooks:
       - id: mypy
         additional_dependencies:
           - httpx
         exclude: docs/.*|tests/.*|noxfile.py
 
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: "v4.6.0"
+    rev: v4.6.0
     hooks:
       - id: check-builtin-literals
       - id: check-added-large-files
@@ -21,7 +21,7 @@ repos:
       - id: trailing-whitespace
 
   - repo: https://github.com/adamchainz/blacken-docs
-    rev: "1.18.0"
+    rev: 1.18.0
     hooks:
       - id: blacken-docs