Update UPB main's protobuf dependency.

This also requires some editing in the rewrites since importing plugin.proto shouldn't require the src prefix after https://github.com/protocolbuffers/protobuf/pull/11991.

PiperOrigin-RevId: 518387501
diff --git a/bazel/workspace_deps.bzl b/bazel/workspace_deps.bzl
index f4725da..370616b 100644
--- a/bazel/workspace_deps.bzl
+++ b/bazel/workspace_deps.bzl
@@ -23,8 +23,8 @@
         _github_archive,
         name = "com_google_protobuf",
         repo = "https://github.com/protocolbuffers/protobuf",
-        commit = "214d3bf409bd16ba4123f5748f5b4c146960dda1",
-        sha256 = "33d40494cbba14142b41f4f560175a315b8740954151b80b29dcdabca30de001",
+        commit = "af34fc6a761e3733ade14d57a05638b468af44af",
+        sha256 = "ebdace4f5911d35f48b3a5ae74ea0c548ec21943c37d436abb75298755102485",
         patches = ["@upb//bazel:protobuf.patch"],
     )
 
diff --git a/upbc/BUILD b/upbc/BUILD
index ae561a5..041ae30 100644
--- a/upbc/BUILD
+++ b/upbc/BUILD
@@ -65,7 +65,7 @@
     name = "plugin_upb_proto",
     base_dir = "",
     google3_src_files = [
-        "src/google/protobuf/compiler/plugin.proto",
+        "net/proto2/compiler/proto/plugin.proto",
         "net/proto2/compiler/proto/profile.proto",
     ],
     google3_src_rules = [
diff --git a/upbc/code_generator_request.proto b/upbc/code_generator_request.proto
index 0b55e69..4d10376 100644
--- a/upbc/code_generator_request.proto
+++ b/upbc/code_generator_request.proto
@@ -2,7 +2,7 @@
 
 package upbc;
 
-import "src/google/protobuf/compiler/plugin.proto";
+import "google/protobuf/compiler/plugin.proto";
 
 message CodeGeneratorRequest {
   message UpbInfo {