Fix double-source-jar error during releases:

```
Building and deploying the android flavor (this may take a while)...
[ERROR] We have duplicated artifacts attached.
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-source-plugin:3.3.0:jar (attach-sources) on project guava: Presumably you have configured maven-source-plugn to execute twice times in your build. You have to configure a classifier for at least on of them. -> [Help 1]
```

I had fixed the same issue with _snapshot_ deployment in cl/559489724 (by no longer passing `source:jar` to `mvn`), but apparently that fix doesn't apply to _release_ deployment. I'm guessing that the relevant part of our release command is `-Psonatype-oss-release`, which (among other things) [activates a `maven-source-plugin` configuration change](https://github.com/google/guava/blob/a78bea41aedba50469641968ee3d98b24836e491/pom.xml#L329-L334): Presumably that introduces a second `maven-source-plugn` execution in much the same way as passing `source:jar` does.

I previously fixed a similar problem in jimfs (cl/536746714) by removing the "normal" `maven-source-plugin` configuration, leaving only the `sonatype-oss-release` configuration in the parent.

I don't remember whether I investigated removing jimfs' `sonatype-oss-release` configuration instead. Probably I should have at least investigated, since that's what we're going with here.

As best I can tell, this doesn't interfere with _snapshot_ source jars, which are produced even without `source:jar`.

(Notice that the configuration that may be the source of the problem was copied from the old `oss-parent` pom. This is at least the second time that that pom's configuration has caused us trouble, the other I recall being cl/492304151—well, and probably the aforementioned jimfs source-jar issue, too.)

This prepares for the release that contains the fix for #6634, among other issues.

RELNOTES=n/a
PiperOrigin-RevId: 572327204

Author: cpovirk

Diff for: android/pom.xml

@@ -23,7 +23,6 @@
     <javac.version>9+181-r4173-1</javac.version>
     <!-- Empty for all JDKs but 9-12 -->
     <maven-javadoc-plugin.additionalJOptions></maven-javadoc-plugin.additionalJOptions>
-    <maven-source-plugin.version>3.3.0</maven-source-plugin.version>
     <project.build.outputTimestamp>2023-02-01T00:00:00Z</project.build.outputTimestamp>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <test.add.opens></test.add.opens>
@@ -172,12 +171,14 @@
         </plugin>
         <plugin>
           <artifactId>maven-source-plugin</artifactId>
-          <version>${maven-source-plugin.version}</version>
+          <version>3.3.0</version>
           <executions>
             <execution>
               <id>attach-sources</id>
-              <phase>post-integration-test</phase>
-              <goals><goal>jar</goal></goals>
+              <phase>verify</phase>
+              <goals>
+                <goal>jar-no-fork</goal>
+              </goals>
             </execution>
           </executions>
         </plugin>
@@ -335,19 +336,10 @@
         <id>sonatype-oss-release</id>
         <build>
           <plugins>
-            <plugin>
-              <groupId>org.apache.maven.plugins</groupId>
-              <artifactId>maven-source-plugin</artifactId>
-              <version>${maven-source-plugin.version}</version>
-              <executions>
-                <execution>
-                  <id>attach-sources</id>
-                  <goals>
-                    <goal>jar-no-fork</goal>
-                  </goals>
-                </execution>
-              </executions>
-            </plugin>
+            <!-- TODO(cpovirk): Consider eliminating the maven-javadoc-plugin
+                 config here, moving anything that we want into the "normal"
+                 plugin config and perhaps removing javadoc:jar from the command
+                 we run for snapshot releases. -->
             <plugin>
               <groupId>org.apache.maven.plugins</groupId>
               <artifactId>maven-javadoc-plugin</artifactId>

Diff for: pom.xml

@@ -23,7 +23,6 @@
     <javac.version>9+181-r4173-1</javac.version>
     <!-- Empty for all JDKs but 9-12 -->
     <maven-javadoc-plugin.additionalJOptions></maven-javadoc-plugin.additionalJOptions>
-    <maven-source-plugin.version>3.3.0</maven-source-plugin.version>
     <project.build.outputTimestamp>2023-02-01T00:00:00Z</project.build.outputTimestamp>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <test.add.opens></test.add.opens>
@@ -173,12 +172,14 @@
         </plugin>
         <plugin>
           <artifactId>maven-source-plugin</artifactId>
-          <version>${maven-source-plugin.version}</version>
+          <version>3.3.0</version>
           <executions>
             <execution>
               <id>attach-sources</id>
-              <phase>post-integration-test</phase>
-              <goals><goal>jar</goal></goals>
+              <phase>verify</phase>
+              <goals>
+                <goal>jar-no-fork</goal>
+              </goals>
             </execution>
           </executions>
         </plugin>
@@ -329,19 +330,10 @@
         <id>sonatype-oss-release</id>
         <build>
           <plugins>
-            <plugin>
-              <groupId>org.apache.maven.plugins</groupId>
-              <artifactId>maven-source-plugin</artifactId>
-              <version>${maven-source-plugin.version}</version>
-              <executions>
-                <execution>
-                  <id>attach-sources</id>
-                  <goals>
-                    <goal>jar-no-fork</goal>
-                  </goals>
-                </execution>
-              </executions>
-            </plugin>
+            <!-- TODO(cpovirk): Consider eliminating the maven-javadoc-plugin
+                 config here, moving anything that we want into the "normal"
+                 plugin config and perhaps removing javadoc:jar from the command
+                 we run for snapshot releases. -->
             <plugin>
               <groupId>org.apache.maven.plugins</groupId>
               <artifactId>maven-javadoc-plugin</artifactId>