Bump maven-source-plugin from 3.0.1 to 3.2.1

Bumps [maven-source-plugin](https://github.com/apache/maven-source-plugin) from 3.0.1 to 3.2.1.
- [Release notes](https://github.com/apache/maven-source-plugin/releases)
- [Commits](https://github.com/apache/maven-source-plugin/compare/maven-source-plugin-3.0.1...maven-source-plugin-3.2.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>
See gh-417.

docs/pom.xml

@@ -36,7 +36,7 @@
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>
 					<artifactId>maven-source-plugin</artifactId>
-					<version>3.0.1</version>
+					<version>3.2.1</version>
 				</plugin>
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>

pom.xml

@@ -229,7 +229,7 @@
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>
 					<artifactId>maven-source-plugin</artifactId>
-					<version>3.0.1</version>
+					<version>3.2.1</version>
 				</plugin>
 
 				<plugin>

spring-cloud-vault-dependencies/pom.xml

@@ -117,7 +117,7 @@
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>
 					<artifactId>maven-source-plugin</artifactId>
-					<version>3.0.1</version>
+					<version>3.2.1</version>
 				</plugin>
 			</plugins>
 		</pluginManagement>