Revert "Fix llvm18 recipe on newer Pop"

This reverts commit f953d63d.

recipes/dev/llvm18/recipe.toml

@@ -35,7 +35,7 @@ COOKBOOK_CONFIGURE_FLAGS=(
     -DLLVM_INCLUDE_EXAMPLES=Off
     -DLLVM_INCLUDE_TESTS=Off
     -DLLVM_INCLUDE_UTILS=Off
-    -DLLVM_TABLEGEN=$(which llvm-tblgen-18)
+    -DLLVM_OPTIMIZED_TABLEGEN=On
     -DLLVM_TARGET_ARCH="$(echo "${TARGET}" | cut -d - -f1)"
     -DLLVM_TARGETS_TO_BUILD=X86 # TODO: get from TARGET
     -DLLVM_TOOL_LLVM_COV_BUILD=Off