Replace S3 streamToBuffer with pipe. (#28993)

* Replace S3 streamToBuffer with pipe.

Signed-off-by: Sydney Achinger <sydneynicoleachinger@spotify.com>

.changeset/cuddly-dodos-allow.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-techdocs-node': patch
+---
+
+Update AWS file retrieval logic from storing file in buffer array to piping to res for better memory efficiency.

plugins/techdocs-node/src/stages/publish/awsS3.ts

@@ -483,7 +483,18 @@ export class AwsS3Publish implements PublisherBase {
           res.setHeader(headerKey, headerValue);
         }
 
-        res.send(await streamToBuffer(resp.Body as Readable));
+        (resp.Body as Readable)
+          .on('error', err => {
+            this.logger.warn(
+              `TechDocs S3 router failed to serve static files from bucket ${this.bucketName} at key ${filePath}: ${err.message}`,
+            );
+            if (!res.headersSent) {
+              res.status(404).send('File Not Found');
+            } else {
+              res.destroy();
+            }
+          })
+          .pipe(res);
       } catch (err) {
         assertError(err);
         this.logger.warn(