fix: override GHPullRequest isPullRequest

src/main/java/org/kohsuke/github/GHPullRequest.java

@@ -492,6 +492,16 @@ public boolean isMerged() throws IOException {
         return merged;
     }
 
+    /**
+     * Since a GHPullRequest is always a pull request, this method always returns true.
+     *
+     * @return true
+     */
+    @Override
+    public boolean isPullRequest() {
+        return true;
+    }
+
     /**
      * Retrieves all the commits associated to this pull request.
      *

src/test/java/org/kohsuke/github/GHEventPayloadTest.java

@@ -1081,6 +1081,7 @@ public void pull_request() throws Exception {
         assertThat(event.getPullRequest().getBase().getLabel(), is("baxterthehacker:main"));
         assertThat(event.getPullRequest().getBase().getSha(), is("9049f1265b7d61be4a8904a9a27120d2064dab3b"));
         assertThat(event.getPullRequest().isMerged(), is(false));
+        assertThat(event.getPullRequest().isPullRequest(), is(true));
         assertThat(event.getPullRequest().getMergeable(), nullValue());
         assertThat(event.getPullRequest().getMergeableState(), is("unknown"));
         assertThat(event.getPullRequest().getMergedBy(), nullValue());