Make it possible to run all tests in Intellij as well

The previous set-up was only working out for Maven.

pom.xml

@@ -123,12 +123,6 @@
           <compilerArgs>
             <arg>--add-modules</arg>
             <arg>jdk.incubator.foreign</arg>
-
-            <!--
-             These two are really only needed for test-compile, but the maven-compiler-plugin cannot express that
-             -->
-            <arg>--patch-module</arg>
-            <arg>io.netty.buffer=${io.netty:netty-buffer:test-jar:tests}</arg>
           </compilerArgs>
         </configuration>
       </plugin>
@@ -176,7 +170,7 @@
           <includes>
             <include>**/*Test*.java</include>
           </includes>
-          <argLine>${argLine.common} ${argLine.printGC} --patch-module io.netty.buffer=${io.netty:netty-buffer:test-jar:tests} --add-modules jdk.incubator.foreign</argLine>
+          <argLine>${argLine.common} ${argLine.printGC} --add-modules jdk.incubator.foreign</argLine>
           <!-- Ensure the whole stacktrace is preserved when an exception is thrown. See https://issues.apache.org/jira/browse/SUREFIRE-1457 -->
           <trimStackTrace>false</trimStackTrace>
         </configuration>
@@ -405,14 +399,6 @@
       <version>${netty.build.version}</version>
       <scope>test</scope>
     </dependency>
-    <dependency>
-      <groupId>io.netty</groupId>
-      <artifactId>netty-buffer</artifactId>
-      <version>${netty.version}</version>
-      <type>test-jar</type>
-      <classifier>tests</classifier>
-      <scope>test</scope>
-    </dependency>
     <dependency>
       <groupId>io.netty</groupId>
       <artifactId>netty-handler</artifactId>

src/test/java/io/netty/buffer/api/adaptor/ByteBufAdaptorTest.java

@@ -15,7 +15,6 @@
  */
 package io.netty.buffer.api.adaptor;
 
-import io.netty.buffer.AbstractByteBufTest;
 import io.netty.buffer.ByteBuf;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;