Don't fallback to Imath from src/deps

If the user explicitely requests to use find_package to use the system Imath it seems wrong to fallback to the delivered Imath

Signed-off-by: Julius Künzel <julius.kuenzel@kde.org>

Author: jlskuz

CMakeLists.txt

@@ -224,13 +224,10 @@ if (NOT "${OTIO_IMATH_LIBS}" STREQUAL "")
     set(OTIO_RESOLVED_IMATH_LIBRARIES "${OTIO_IMATH_LIBS}")
     set(USE_DEPS_IMATH OFF)
 elseif(OTIO_FIND_IMATH)
-    find_package(Imath QUIET)
+    set(USE_DEPS_IMATH OFF)
+    find_package(Imath REQUIRED)
     if (Imath_FOUND)
         message(STATUS "Found Imath 3 at ${Imath_CONFIG}")
-        set(USE_DEPS_IMATH OFF)
-    else()
-        message(STATUS "Imath 3 was not found, using src/deps/Imath")
-        set(USE_DEPS_IMATH ON)
     endif()
 else()
     message(STATUS "Using src/deps/Imath by default")