[libc++] Add libc++ clang-formatting commit to git-blame-ignore-revs file
diff --git a/.git-blame-ignore-revs b/.git-blame-ignore-revs
index 74b1e92..739fd38 100644
--- a/.git-blame-ignore-revs
+++ b/.git-blame-ignore-revs
@@ -70,3 +70,6 @@
 
 # [libc++] Replace uses of _VSTD:: by std:: (#74331)
 77a00c0d546cd4aa8311b5b9031ae9ea8cdb050c
+
+# [libc++] Format the code base (#74334)
+9783f28cbb155e4a8d49c12e1c60ce14dcfaf0c7