Use file(STRINGS) to read go_tests.txt

Inspired by
https://boringssl-review.googlesource.com/c/boringssl/+/61245, though it
looks like we do still need CMAKE_CONFIGURE_DEPENDS to tell CMake to
rerun itself.

Change-Id: Iec2d23590dd45c647c5c53dc80aa8420795a7e73
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/61265
Auto-Submit: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

CMakeLists.txt

@@ -570,10 +570,7 @@ else()
   add_custom_target(fips_specific_tests_if_any)
 endif()
 
-# Read util/go_tests.txt into a CMake variable.
-file(READ util/go_tests.txt GO_TESTS)
-string(REPLACE "\n" ";" GO_TESTS "${GO_TESTS}")
-list(REMOVE_ITEM GO_TESTS "")
+file(STRINGS util/go_tests.txt GO_TESTS)
 set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS
              util/go_tests.txt)