[freetype2] Reenable usan

The latest version of freetype2 fixes the usan errors that came up
when we enabled the sanitizer. This cl reenables usan for the project.

Bug: fxbug.dev/46923
Test: the following instructions work around problems connecting to
the package server from arm64.

1. fx set with core.arm64 and //src/fonts/font_info:font_info_tests and
//garnet/bin/run_test_component:run-test-component-pkg added to base.
2. fx emu --experiment-arm64 -m 8192 -N -I qemu -u /usr/bin/shortleash-upscript
3. run fuchsia-pkg://fuchsia.com/font_info_tests#meta/font_info_test.cmx

Change-Id: I1e0ab01482d3471657e6fc4d3b93cf7083f6222d
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/freetype2/+/460031
Reviewed-by: Shai Barack <shayba@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index 34deeb8..22bdbe1 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -85,9 +85,6 @@
       "src/cff/cff.c",           # OpenType, (.cff, .cef)
       "src/truetype/truetype.c", # TrueType
-    # TODO(46923): UBSan has found an instance of undefined behavior in this target.
-    # Disable UBSan for this target temporarily until it is migrated into CI/CQ.
-    configs += [ "//build/config:temporarily_disable_ubsan_do_not_use" ]
     defines = [