[red-knot] Shorten the paths for some mdtest files (#14267)

.pre-commit-config.yaml

@@ -53,7 +53,7 @@ repos:
         files: '^crates/.*/resources/mdtest/.*\.md'
         exclude: |
           (?x)^(
-            .*?invalid(_.+)_syntax.md
+            .*?invalid(_.+)*_syntax\.md
           )$
         additional_dependencies:
           - black==24.10.0