Disable DilithiumTest.BitFlips test

This test is very slow. Even BoringSSL's CI got noticeably slower after
it was enabled. It should hopefully be redundant with the test vectors,
supposing the test vectors were generated well.

(The test is still available to be run manually.)

Bug: chromium:341639202
Change-Id: Ica248c6643458988e45e50d5ec80718b5ff4bb5f
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/68627
Auto-Submit: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/crypto/dilithium/dilithium_test.cc b/crypto/dilithium/dilithium_test.cc
index 3918142..b0bb2ed 100644
--- a/crypto/dilithium/dilithium_test.cc
+++ b/crypto/dilithium/dilithium_test.cc
@@ -28,7 +28,8 @@
 #include "./internal.h"
 
 
-TEST(DilithiumTest, BitFlips) {
+// This test is very slow, so it is disabled by default.
+TEST(DilithiumTest, DISABLED_BitFlips) {
   auto encoded_public_key =
       std::make_unique<uint8_t[]>(DILITHIUM_PUBLIC_KEY_BYTES);
   auto priv = std::make_unique<DILITHIUM_private_key>();