always update release PR, even if title/body do not change (#187)

src/manifest.ts

@@ -1146,15 +1146,15 @@ export class Manifest {
     existing: PullRequest,
     pullRequest: ReleasePullRequest
   ): Promise<PullRequest | undefined> {
-    // If unchanged, no need to push updates
+    // If the body and title are unchanged, update anyways since some commits that are not included in the PR body
+    // may have been added
     if (
       existing.title === pullRequest.title.toString() &&
       existing.body === pullRequest.body.toString()
     ) {
       this.logger.info(
-        `PR https://github.com/${this.repository.owner}/${this.repository.repo}/pull/${existing.number} remained the same`
+        `PR https://github.com/${this.repository.owner}/${this.repository.repo}/pull/${existing.number} remained the same - continuing anyways`
       );
-      return undefined;
     }
 
     const updatedPullRequest = await this.github.updatePullRequest(