[test][embedded] Declare embedded-volatile as a test depdency

We fail to build the embedded variant of this target before running the
embedded/volatile* tests, then fail to import `_Volatile`.

Author: Nuri Amari

test/CMakeLists.txt

@@ -326,6 +326,9 @@ foreach(SDK ${SWIFT_SDKS})
         if(TARGET "embedded-synchronization")
           list(APPEND test_dependencies "embedded-synchronization")
         endif()
+        if(TARGET "embedded-volatile")
+          list(APPEND test_dependencies "embedded-volatile")
+        endif()
       endif()
 
       if(NOT "${COVERAGE_DB}" STREQUAL "")