build(deps): bump minimum required tomlkit to >=0.11.0

TOMLDocument is missing the `unwrap()` function in `v0.10.2` which
causes an AttributeError to occur when attempting to read a the text
in `pyproject.toml` as discovered with #834

Resolves: #834

pyproject.toml

@@ -27,7 +27,7 @@ dependencies = [
   "requests>=2.25,<3",
   "jinja2>=3.1.2,<4",
   "python-gitlab>=2,<5",
-  "tomlkit~=0.10",
+  "tomlkit~=0.11",
   "dotty-dict>=1.3.0,<2",
   "importlib-resources>=5.7,<7",
   "pydantic>=2,<3",