Explicitly refresh and rebuild test project after .classpath change

This hopefully fixes spurious test failures, like this one:

ProjectPropertiesModelTest.testProjectClasspath:584 Found these URIs:
[file:/usr/lib/jvm/temurin-21-jdk-amd64/lib/jrt-fs.jar,
file:/home/runner/work/pmd-eclipse-plugin/pmd-eclipse-plugin/net.sourceforge.pmd.eclipse.plugin.test/target/work/data/ProjectPropertiesModelTest/bin/]
expected: 6 but was: 2

Author: adangel

net.sourceforge.pmd.eclipse.plugin.test/src/main/java/net/sourceforge/pmd/eclipse/runtime/properties/ProjectPropertiesModelTest.java

@@ -573,6 +573,11 @@ public void testProjectClasspath() throws Exception {
             + "    <classpathentry kind=\"lib\" path=\"/ExternalProject/sample-lib4.jar\"/>\n"
             + "</classpath>\n";
         file.setContents(IOUtils.toInputStream(newClasspathContent, "UTF-8"), 0, null);
+        // refresh, so that changed .classpath file is considered
+        this.testProject.refreshLocal(IResource.DEPTH_INFINITE, null);
+        // rebuild again, so that changed classpath is configured on java project
+        this.testProject.build(IncrementalProjectBuilder.FULL_BUILD, null);
+
         final IProjectPropertiesManager mgr = PMDPlugin.getDefault().getPropertiesManager();
         IProjectProperties model = mgr.loadProjectProperties(this.testProject);
         URLClassLoader auxClasspath = (URLClassLoader) model.getAuxClasspath(); // NOPMD: don't close auxclasspath in test, this should be done by the plugin