fix: install header patterns use wrong csrc/ prefix and missing - #6051

@greptile-apps thanks for catching that. I removed the EXCLUDE modifier from C++23/utility and struct.inl so the installed header tree includes the transitive headers required by base.h and polymorphic_value.h. C++20/compare remains excluded because no installed public header currently pulls it in. The updated commit is e8143f52b.

That distinction makes sense. Looking at the current diff state:

PATTERN "C++20/compare" EXCLUDE
PATTERN "C++23/utility"
PATTERN "struct.inl")

The logic is correct — FILES_MATCHING treats patterns without EXCLUDE as additional inclusion filters, so C++23/utility and struct.inl will be installed alongside *.h files, while C++20/compare is explicitly excluded.

One observation worth considering: the sanity test in test_cmake_sanity.py only guards against the old bad patterns reappearing, but doesn't assert the positive side — that C++23/utility and struct.inl are present without EXCLUDE. If someone later incorrectly adds EXCLUDE to those lines (or drops them entirely), the test won't catch it. You might want to add assertions like:

# Transitive headers required by installed public headers must be present
# without EXCLUDE.
for required in (
 'PATTERN "C++23/utility"',
 'PATTERN "struct.inl"',
):
 self.assertIn(required, block)
 # Ensure the line is not followed by EXCLUDE
 self.assertNotIn(required + " EXCLUDE", block)

Otherwise the fix looks good.