remove unnecessary includes (#4451)

CMakeLists.txt

@@ -493,9 +493,7 @@ if (BUILD_TESTING)
         string(REGEX REPLACE ".+\\/(.+)\\.c" "\\1" test_case_name ${test_case})
 
         add_executable(${test_case_name} ${test_case})
-        target_include_directories(${test_case_name} PRIVATE api)
         target_include_directories(${test_case_name} PRIVATE ./)
-        target_include_directories(${test_case_name} PRIVATE tests)
         target_link_libraries(${test_case_name} PRIVATE testss2n)
         if (S2N_INTERN_LIBCRYPTO)
             # if libcrypto was interned, rewrite libcrypto symbols so use of internal functions will link correctly
@@ -521,15 +519,11 @@ if (BUILD_TESTING)
 
     add_executable(s2nc "bin/s2nc.c" "bin/echo.c" "bin/https.c" "bin/common.c")
     target_link_libraries(s2nc ${PROJECT_NAME})
-
-    target_include_directories(s2nc PRIVATE api)
     target_compile_options(s2nc PRIVATE -std=gnu99)
 
 
     add_executable(s2nd "bin/s2nd.c" "bin/echo.c" "bin/https.c" "bin/common.c")
     target_link_libraries(s2nd ${PROJECT_NAME})
-
-    target_include_directories(s2nd PRIVATE api)
     target_compile_options(s2nd PRIVATE -std=gnu99)
 
     if(S2N_LTO)