deps: update protobuf runtime to 4.33.0

Author: diegomarquezp

pom.xml

@@ -58,6 +58,13 @@
 
   <dependencyManagement>
     <dependencies>
+      <dependency>
+        <groupId>com.google.protobuf</groupId>
+        <artifactId>protobuf-bom</artifactId>
+        <version>4.33.0</version>
+        <type>pom</type>
+        <scope>import</scope>
+      </dependency>
       <dependency>
         <groupId>com.google.cloud</groupId>
         <artifactId>google-cloud-spanner-bom</artifactId>