Update boringssl to 9cac8a6b38c1cbd45c77aee108411d588da006fe

Problem:
- BoringSSL needed to be updated since it's been a while

This PR:
- Updates BoringSSL to master as of June 12, 2024
  - SHA 9cac8a6b38c1cbd45c77aee108411d588da006fe

Testing done:
- Full unit test suite still passes
- chip-tool pairing passes
- Python tests pass when built with BoringSSL

.gitmodules

@@ -252,6 +252,7 @@
 [submodule "third_party/boringssl/repo/src"]
 	path = third_party/boringssl/repo/src
 	url = https://github.com/google/boringssl.git
+	branch = master
 [submodule "third_party/mt793x_sdk/filogic"]
 	path = third_party/mt793x_sdk/filogic
 	url = https://github.com/MediaTek-Labs/genio-matter-bsp.git