Pin build requirements (#1076)

To make sure installing the driver won't randomly start failing in the future
because an unanticipated updated to one of the build libraries gets published,
we pin them to a fixed version and bump them manually.

Author: robsdedude

pyproject.toml

@@ -64,9 +64,9 @@ pyarrow = ["pyarrow >= 1.0.0"]
 
 [build-system]
 requires = [
-    "setuptools >= 66.1.0",
+    "setuptools == 68.0.0",  # dropped support for Python 3.7 in 68.1.0
     # TODO: 6.0 - can be removed once `setup.py` is simplified
-    "tomlkit ~= 0.11.6",
+    "tomlkit == 0.11.8",
 ]
 build-backend = "setuptools.build_meta"