chore(cmat): drop legacy warning flags

Comment out the loop that copied BASE_OPTIONS (minus -Werror) into
CMAT_OPTIONS so exercise targets no longer inherit the project
warning flags.

Co-authored-by: Qwen 3.8 27B <qwen3.8_27b-q3_k_xl@lmstudio.local>

cmat/CMakeLists.txt

@@ -18,11 +18,11 @@
 # Legacy course material: keep the project's warning flags but drop -Werror;
 # these old sources produce warnings that must not block the build.
 set(CMAT_OPTIONS "")
-foreach (opt IN LISTS BASE_OPTIONS)
-    if (NOT opt STREQUAL "-Werror" AND NOT opt STREQUAL "/WX")
-        list(APPEND CMAT_OPTIONS "${opt}")
-    endif()
-endforeach()
+# foreach (opt IN LISTS BASE_OPTIONS)
+#     if (NOT opt STREQUAL "-Werror" AND NOT opt STREQUAL "/WX")
+#         list(APPEND CMAT_OPTIONS "${opt}")
+#     endif()
+# endforeach()
 
 # ------------------------------------------------------------------------------
 # Keyboard/Screen support (DOS_Unix/)