build(deps-dev): bump types-markdown from 3.10.2.20260408 to 3.10.2.20260518 (#281)

Bumps [types-markdown](https://github.com/python/typeshed) from
3.10.2.20260408 to 3.10.2.20260518.
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Author: frequenz-auto-dependabot[bot]

pyproject.toml

@@ -77,7 +77,7 @@ dev-mkdocs = [
 dev-mypy = [
   "mypy == 2.1.0",
   "grpc-stubs == 1.53.0.6",
-  "types-Markdown == 3.10.2.20260408",
+  "types-Markdown == 3.10.2.20260518",
   "types-protobuf == 7.34.1.20260518",
   # For checking the noxfile, docs/ script, and tests
   "frequenz-client-microgrid[dev-mkdocs,dev-noxfile,dev-pytest]",