fix(ci): omit Cython .pxd and cyruntime.pxi from coverage reports

Signed-off-by: Rui Luo <ruluo@nvidia.com>

Author: rluo8

.coveragerc

@@ -11,11 +11,13 @@ plugins = Cython.Coverage
 core = ctrace
 branch = False
 relative_files = True
-# Omits specific definition files that causes plugin errors
+# Cython.Coverage cannot FileReporter declaration files (no parent-.c walk for
+# .pxd) or includes whose generated .cpp is not beside the source
+# (cyruntime.pxi). Keep system/*.pxi and _lib/utils.pxi: those have a sibling
+# translation unit on the combine runner. Must be [run], not [report].
 omit =
-    */windll.pxd
-    */_lib/windll.pxd
-    */_lib/utils.pxd
+    */*.pxd
+    */cyruntime.pxi
 
 [report]
 show_missing = true