deps: protobuf 3.17.3 (#2109)

@suztomo

Author: elharo

boms/cloud-oss-bom/pom.xml

@@ -49,7 +49,7 @@
     <google.cloud.core.version>1.95.0</google.cloud.core.version>
     <io.grpc.version>1.38.0</io.grpc.version>
     <http.version>1.39.2</http.version>
-    <protobuf.version>3.17.2</protobuf.version>
+    <protobuf.version>3.17.3</protobuf.version>
     <!-- We don't use gax-bom because it includes the artifacts with 'testlib' classifier.
         When updating gax.version, update gax.httpjson.version too. -->
     <gax.version>1.65.0</gax.version>