Use cog-runtime for some images

Author: nevillelyh

canary/cog.yaml

@@ -1,3 +1,4 @@
 build:
-  python_version: "3.8"
+  python_version: "3.13"
+  cog_runtime: true
 predict: "predict.py:Predictor"

hello-image/cog.yaml

@@ -1,3 +1,4 @@
 build:
-  python_version: "3.11"
+  python_version: "3.13"
+  cog_runtime: true
 predict: "predict.py:Predictor"

hello-image/predict.py

@@ -1,5 +1,9 @@
 from cog import BasePredictor, Path
+from tempfile import NamedTemporaryFile
 
 class Predictor(BasePredictor):
     def predict(self) -> Path:
-        return Path("hello.webp")
+        # Copy output file, workaround for some cog version deleting output after upload
+        with open("/tmp/hello.webp", "wb") as f:
+            f.write(open("hello.webp", "rb").read())
+        return Path("/tmp/hello.webp")