Add dummy parameter to prevent warnings with jgit as timestamp provider

Maven 3.9 complains of "missing" parameters even if we need them for the
jgit provider.

This adds two dummy parameters so maven is happy again.

Fix #2080

(cherry picked from commit 0ffb59a)

tycho-buildtimestamp-jgit/src/main/java/org/eclipse/tycho/extras/buildtimestamp/jgit/JGitBuildTimestampProvider.java

@@ -93,6 +93,9 @@
  */
 @Component(role = BuildTimestampProvider.class, hint = "jgit")
 public class JGitBuildTimestampProvider implements BuildTimestampProvider {
+	private static final String PARAMETER_JGIT_IGNORE = "jgit.ignore";
+
+	private static final String PARAMETER_JGIT_DIRTY_WORKING_TREE = "jgit.dirtyWorkingTree";
 
 	@Requirement(hint = "default")
 	private BuildTimestampProvider defaultTimestampProvider;
@@ -112,7 +115,7 @@ public static DirtyBehavior getDirtyWorkingTreeBehaviour(MojoExecution execution
 			if (pluginConfiguration == null) {
 				return defaultBehaviour;
 			}
-			Xpp3Dom dirtyWorkingTreeDom = pluginConfiguration.getChild("jgit.dirtyWorkingTree");
+			Xpp3Dom dirtyWorkingTreeDom = pluginConfiguration.getChild(PARAMETER_JGIT_DIRTY_WORKING_TREE);
 			if (dirtyWorkingTreeDom == null) {
 				return defaultBehaviour;
 			}
@@ -219,7 +222,7 @@ private static String getIgnoreFilter(MojoExecution execution) {
 		if (pluginConfiguration == null) {
 			return null;
 		}
-		Xpp3Dom ignoreDom = pluginConfiguration.getChild("jgit.ignore");
+		Xpp3Dom ignoreDom = pluginConfiguration.getChild(PARAMETER_JGIT_IGNORE);
 		if (ignoreDom == null) {
 			return null;
 		}

tycho-packaging-plugin/src/main/java/org/eclipse/tycho/buildversion/BuildQualifierMojo.java

@@ -116,12 +116,26 @@ public class BuildQualifierMojo extends AbstractVersionMojo {
     @Parameter(property = "mojoExecution", readonly = true)
     protected MojoExecution execution;
 
-    @Component(role = BuildTimestampProvider.class)
-    protected Map<String, BuildTimestampProvider> timestampProviders;
+	@Component(role = BuildTimestampProvider.class)
+	protected Map<String, BuildTimestampProvider> timestampProviders;
 
 	@Component
 	private BuildPropertiesParser buildPropertiesParser;
 
+	/**
+	 * This is only a dummy parameter used to prevent maven from complaining about
+	 * "unknown" parameters when using the jgit extension
+	 */
+	@Parameter(alias = "jgit.dirtyWorkingTree")
+	private String dummy1;
+
+	/**
+	 * This is only a dummy parameter used to prevent maven from complaining about
+	 * "unknown" parameters when using the jgit extension
+	 */
+	@Parameter(alias = "jgit.ignore")
+	private String dummy2;
+
     // setter is needed to make sure we always use UTC
     public void setFormat(String formatString) {
         format = new SimpleDateFormat(formatString);