Update third_party/upb to the latest

bazel/grpc_deps.bzl

@@ -206,9 +206,9 @@ def grpc_deps():
     if "upb" not in native.existing_rules():
         http_archive(
             name = "upb",
-            sha256 = "1107ca1ea9aef3880b60ffb2179d06970394f1d6b62d0565e72b544b4924468d",
-            strip_prefix = "upb-1ee1e362565f681fdd46f16bf9f70f51c905ddd4",
-            url = "https://github.com/protocolbuffers/upb/archive/1ee1e362565f681fdd46f16bf9f70f51c905ddd4.tar.gz",
+            sha256 = "73deded75313f80779eba109c32f3c59a813addf5064bf6e7c213fca1e7d8e32",
+            strip_prefix = "upb-423ea5ca9ce8da69611e6e95559efcb3a1ba8ad8",
+            url = "https://github.com/protocolbuffers/upb/archive/423ea5ca9ce8da69611e6e95559efcb3a1ba8ad8.tar.gz",
         )
     if "envoy_api" not in native.existing_rules():
         http_archive(

third_party/upb

@@ -1 +1 @@
-Subproject commit 1ee1e362565f681fdd46f16bf9f70f51c905ddd4
+Subproject commit 423ea5ca9ce8da69611e6e95559efcb3a1ba8ad8

tools/run_tests/sanity/check_submodules.sh

@@ -40,7 +40,7 @@ cat << EOF | awk '{ print $1 }' | sort > "$want_submodules"
  9245d481eb3e890f708ff2d7dadf2a10c04748ba third_party/libcxxabi (heads/release_60)
  09745575a923640154bcf307fba8aedff47f240a third_party/protobuf (v3.7.0-rc.2-247-g09745575)
  e143189bf6f37b3957fb31743df6a1bcf4a8c685 third_party/protoc-gen-validate (v0.0.10)
- 1ee1e362565f681fdd46f16bf9f70f51c905ddd4 third_party/upb (heads/master)
+ 423ea5ca9ce8da69611e6e95559efcb3a1ba8ad8 third_party/upb (heads/master)
  cacf7f1d4e3d44d871b605da3b647f07d718623f third_party/zlib (v1.2.11)
 EOF