Downgrade to a version of plexus-io from before a performance improvement was reverted.

(See codehaus-plexus/plexus-io#109.)

This downgrade reduces the time for a clean `mvn source:jar-no-fork -f guava` on our Google workstations from ~53s to ~1s.

(I also upgraded `maven-source-plugin` itself while I was in the area. We still don't have a great way to automatically update Guava _plugins_, only _deps_, as noted offhand in cl/526651811 and discussed slightly more in cl/554548816.)

RELNOTES=n/a
PiperOrigin-RevId: 650382872

Author: cpovirk

android/pom.xml

@@ -163,7 +163,7 @@
         </plugin>
         <plugin>
           <artifactId>maven-source-plugin</artifactId>
-          <version>3.3.0</version>
+          <version>3.3.1</version>
           <executions>
             <execution>
               <id>attach-sources</id>
@@ -172,6 +172,14 @@
               </goals>
             </execution>
           </executions>
+          <dependencies>
+            <dependency>
+              <groupId>org.codehaus.plexus</groupId>
+              <artifactId>plexus-io</artifactId>
+              <!-- DO NOT UPGRADE this past 3.4.1 until https://github.com/codehaus-plexus/plexus-io/issues/109 is fixed. -->
+              <version>3.4.1</version>
+            </dependency>
+          </dependencies>
         </plugin>
         <plugin>
           <groupId>org.codehaus.mojo</groupId>

pom.xml

@@ -164,7 +164,7 @@
         </plugin>
         <plugin>
           <artifactId>maven-source-plugin</artifactId>
-          <version>3.3.0</version>
+          <version>3.3.1</version>
           <executions>
             <execution>
               <id>attach-sources</id>
@@ -173,6 +173,14 @@
               </goals>
             </execution>
           </executions>
+          <dependencies>
+            <dependency>
+              <groupId>org.codehaus.plexus</groupId>
+              <artifactId>plexus-io</artifactId>
+              <!-- DO NOT UPGRADE this past 3.4.1 until https://github.com/codehaus-plexus/plexus-io/issues/109 is fixed. -->
+              <version>3.4.1</version>
+            </dependency>
+          </dependencies>
         </plugin>
         <plugin>
           <groupId>org.codehaus.mojo</groupId>