deps: upgrade protobuf runtime to 4.33.2

Author: blakeli0

gapic-generator-java-pom-parent/pom.xml

@@ -32,7 +32,7 @@
     <google.http-client.version>2.0.3</google.http-client.version>
     <gson.version>2.12.1</gson.version>
     <guava.version>33.5.0-jre</guava.version>
-    <protobuf.version>4.33.0</protobuf.version>
+    <protobuf.version>4.33.2</protobuf.version>
     <opentelemetry.version>1.52.0</opentelemetry.version>
     <errorprone.version>2.42.0</errorprone.version>
     <j2objc-annotations.version>3.1</j2objc-annotations.version>