Remove old IntelliJ dependency

See gh-359

Author: philwebb

Diff for: spring-javaformat-intellij-idea/spring-javaformat-intellij-idea-plugin/pom.xml

@@ -58,12 +58,6 @@
 			<version>${project.version}</version>
 			<scope>provided</scope>
 		</dependency>
-		<dependency>
-			<groupId>io.spring.javaformat.intellij.idea</groupId>
-			<artifactId>platform-impl</artifactId>
-			<version>${project.version}</version>
-			<scope>provided</scope>
-		</dependency>
 		<dependency>
 			<groupId>io.spring.javaformat.intellij.idea</groupId>
 			<artifactId>util</artifactId>