Fix Maven dependency convergence errors

[ivanauth]

Summary

Resolves dependency conflicts introduced in #151 that cause maven-enforcer-plugin convergence failures for downstream Maven users.

Changes

• Add exclusion for proto-google-common-protos from grpc-protobuf to prevent version 2.59.2 from conflicting with 2.61.3
• Add exclusions to protovalidate and pgv-java-stub for transitive dependencies that conflict with SDK versions
• Explicitly declare aligned versions:
  • protobuf-java: 4.32.1
  • protobuf-java-util: 4.32.1
  • proto-google-common-protos: 2.61.3
  • gson: 2.11.0
  • re2j: 1.8

Testing

• Build completed successfully: ./gradlew clean build
• Verified dependency convergence with ./gradlew dependencies --configuration runtimeClasspath
• All conflicting dependencies now resolve to single versions

Fixes dependency convergence errors reported by users upgrading to v1.5.2.

[ivanauth]

Generated POM Comparison

here's what changes in the Maven POM:

Before (main): protovalidate and pgv-java-stub have no exclusions

After (this PR): Both dependencies exclude conflicting transitives, and explicit versions are declared

View POM diff

   <dependency>
     <groupId>build.buf</groupId>
     <artifactId>protovalidate</artifactId>
     <version>1.0.0</version>
     <scope>runtime</scope>
+    <exclusions>
+      <exclusion>
+        <groupId>com.google.protobuf</groupId>
+        <artifactId>protobuf-java</artifactId>
+      </exclusion>
+      <exclusion>
+        <groupId>com.google.code.gson</groupId>
+        <artifactId>gson</artifactId>
+      </exclusion>
+      <exclusion>
+        <groupId>com.google.protobuf</groupId>
+        <artifactId>protobuf-java-util</artifactId>
+      </exclusion>
+      <exclusion>
+        <groupId>com.google.re2j</groupId>
+        <artifactId>re2j</artifactId>
+      </exclusion>
+    </exclusions>
   </dependency>
   <dependency>
     <groupId>build.buf.protoc-gen-validate</groupId>
     <artifactId>pgv-java-stub</artifactId>
     <version>1.2.1</version>
     <scope>runtime</scope>
+    <exclusions>
+      <exclusion>
+        <groupId>com.google.protobuf</groupId>
+        <artifactId>protobuf-java</artifactId>
+      </exclusion>
+      <exclusion>
+        <groupId>com.google.code.gson</groupId>
+        <artifactId>gson</artifactId>
+      </exclusion>
+      <exclusion>
+        <groupId>com.google.protobuf</groupId>
+        <artifactId>protobuf-java-util</artifactId>
+      </exclusion>
+      <exclusion>
+        <groupId>com.google.re2j</groupId>
+        <artifactId>re2j</artifactId>
+      </exclusion>
+    </exclusions>
   </dependency>
+  <dependency>
+    <groupId>com.google.protobuf</groupId>
+    <artifactId>protobuf-java-util</artifactId>
+    <version>4.32.1</version>
+    <scope>runtime</scope>
+  </dependency>
+  <dependency>
+    <groupId>com.google.code.gson</groupId>
+    <artifactId>gson</artifactId>
+    <version>2.11.0</version>
+    <scope>runtime</scope>
+  </dependency>
+  <dependency>
+    <groupId>com.google.re2j</groupId>
+    <artifactId>re2j</artifactId>
+    <version>1.8</version>
+    <scope>runtime</scope>
+  </dependency>

This ensures Maven sees only one version of each library, passing enforcer convergence checks.

[tstirrat15]

Nice. Thank you!