samples/wasm-c-api: skip aot compilation unless necessary

Author: yamt

samples/wasm-c-api/CMakeLists.txt

@@ -129,7 +129,7 @@ if (${WAT2WASM_VERSION} VERSION_LESS 1.0.26)
   set(WAT2WASM_FLAGS "--enable-reference-types")
 endif ()
 
-if(${WAMR_BUILD_AOT} EQUAL 1)
+if(${WAMR_BUILD_AOT} EQUAL 1 AND ${WAMR_BUILD_INTERP} EQUAL 0)
   ## locate wamrc
   find_program(WAMRC
     wamrc