Remove idioms in code comments (#3809)

.github/workflows/ci.yml

@@ -667,7 +667,7 @@ jobs:
 
 
   # This verifies that the documentation is not horribly broken, and does a
-  # basic sanity check on the SDist.
+  # basic validation check on the SDist.
   doxygen:
     name: "Documentation build test"
     runs-on: ubuntu-latest

docs/advanced/pycpp/numpy.rst

@@ -87,7 +87,7 @@ buffer objects (e.g. a NumPy matrix).
             /* Request a buffer descriptor from Python */
             py::buffer_info info = b.request();
 
-            /* Some sanity checks ... */
+            /* Some basic validation checks ... */
             if (info.format != py::format_descriptor<Scalar>::format())
                 throw std::runtime_error("Incompatible format: expected a double array!");