build: exclude ccdbrcdb's protobuf

Author: c-dilks

pom.xml

@@ -181,7 +181,7 @@
       <dependency>
         <groupId>org.jlab.coda</groupId>
         <artifactId>xmsg</artifactId>
-        <version>2.5</version> <!-- WARNING: if changed, check the `com.google.protobuf:protobuf-java` version; see `docs/dependency_conflicts.md` -->
+        <version>2.5</version>
       </dependency>
 
       <dependency>
@@ -230,7 +230,18 @@
       <dependency>
         <groupId>org.jlab.ccdbrcdb</groupId>
         <artifactId>ccdbrcdb</artifactId>
-        <version>2.1</version> <!-- WARNING: if changed, check the `com.google.protobuf:protobuf-java` version; see `docs/dependency_conflicts.md` -->
+        <version>2.1</version>
+        <exclusions>
+          <exclusion>
+            <!--
+              protobuf is transitive via `mysql-connector-j` and is only needed for
+              the X DevAPI (MySQL X Protocol); it also conflicts with the version
+              used by `xmsg`, so we exclude it here
+            -->
+            <groupId>com.google.protobuf</groupId>
+            <artifactId>protobuf-java</artifactId>
+          </exclusion>
+        </exclusions>
       </dependency>
 
       <dependency>
@@ -267,7 +278,7 @@
 
       <!-- BEGIN DEPENDENCY CONFLICT RESOLUTION -->
       <!--
-        the following dependency versions are specified to resolve dependency tree conflicts
+        the following dependency versions are pinned to resolve dependency tree conflicts
         - see also exclusions in `maven-enforcer-plugin`
         - see `docs/dependency_conflicts.md` for more info
       -->
@@ -283,16 +294,6 @@
         <version>0.4.8</version> <!-- WARNING: if changed, see `docs/dependency_conflicts.md` -->
       </dependency>
 
-      <!-- resolve conflicting `com.google.protobuf:protobuf-java` by choosing the latest used by
-          - `org.jlab.ccdbrcdb:ccdbrcdb`
-          - `org.jlab.coda:xmsg`
-      -->
-      <dependency>
-        <groupId>com.google.protobuf</groupId>
-        <artifactId>protobuf-java</artifactId>
-        <version>4.31.1</version> <!-- WARNING: if changed, see `docs/dependency_conflicts.md` -->
-      </dependency>
-
       <!-- resolve conflict between `j4ml:j4ml-clas12` and `clas-tracking`
            by using the version of `org.ejml:ejml-simple` used by `j4ml:j4ml-clas12:jar:0.9-SNAPSHOT` -->
       <dependency>