Add exclude_lines to the coveraage report config

.coveragerc

@@ -6,3 +6,20 @@ omit =
 
 [report]
 include = piptools/*, tests/*
+
+# Regexes for lines to exclude from consideration
+exclude_lines =
+    # Have to re-enable the standard pragma:
+    pragma: no cover
+
+    # Don't complain about missing debug-only code:
+    def __repr__
+
+    # Don't complain if tests don't hit defensive assertion code:
+    raise AssertionError
+    raise NotImplementedError
+    return NotImplemented
+
+    # Don't complain if non-runnable code isn't run:
+    if (0|False|TYPE_CHECKING):
+    if __name__ == .__main__.: