Bump types-protobuf from 7.34.1.20260408 to 7.34.1.20260518 (#303)

Bumps [types-protobuf](https://github.com/python/typeshed) from
7.34.1.20260408 to 7.34.1.20260518.
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Author: frequenz-auto-dependabot[bot]

pyproject.toml

@@ -68,7 +68,7 @@ dev-mkdocs = [
 dev-mypy = [
   "mypy == 1.20.2",
   "types-Markdown == 3.10.2.20260518",
-  "types-protobuf == 7.34.1.20260408",
+  "types-protobuf == 7.34.1.20260518",
   # For checking the noxfile, docs/ script, and tests
   "frequenz-client-reporting[dev-mkdocs,dev-noxfile,dev-pytest]",
   "pandas-stubs >= 2, < 4",  # Only required for example