Bump dockerfile-maven-plugin from 1.4.12 to 1.4.13 (#1438)

Bumps [dockerfile-maven-plugin](https://github.com/spotify/dockerfile-maven) from 1.4.12 to 1.4.13.
- [Release notes](https://github.com/spotify/dockerfile-maven/releases)
- [Changelog](https://github.com/spotify/dockerfile-maven/blob/master/CHANGELOG.md)
- [Commits](https://github.com/spotify/dockerfile-maven/compare/v1.4.12...v1.4.13)

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

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

docker/spring-cloud-contract-docker/pom.xml

@@ -110,7 +110,7 @@
 			<plugin>
 				<groupId>com.spotify</groupId>
 				<artifactId>dockerfile-maven-plugin</artifactId>
-				<version>1.4.12</version>
+				<version>1.4.13</version>
 				<executions>
 					<execution>
 						<id>default</id>

docker/spring-cloud-contract-stub-runner-docker/pom.xml

@@ -66,7 +66,7 @@
 			<plugin>
 				<groupId>com.spotify</groupId>
 				<artifactId>dockerfile-maven-plugin</artifactId>
-				<version>1.4.12</version>
+				<version>1.4.13</version>
 				<executions>
 					<execution>
 						<id>default</id>