Update validate-pyproject requirement from <0.17 to <0.19

Updates the requirements on [validate-pyproject](https://github.com/abravalheri/validate-pyproject) to permit the latest version.
- [Release notes](https://github.com/abravalheri/validate-pyproject/releases)
- [Changelog](https://github.com/abravalheri/validate-pyproject/blob/main/CHANGELOG.rst)
- [Commits](abravalheri/validate-pyproject@v0.0.1...v0.18)

---
updated-dependencies:
- dependency-name: validate-pyproject
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

pyproject.toml

@@ -115,7 +115,7 @@ develop = [
   "poethepoet<0.27",
   "pyproject-fmt<2.2",
   "ruff<0.5",
-  "validate-pyproject<0.17",
+  "validate-pyproject<0.19",
 ]
 docs = [
   "furo",