Made grype work with file

Dockerfile

@@ -1,4 +1,4 @@
-FROM public.ecr.aws/docker/library/alpine:3.20
+FROM public.ecr.aws/docker/library/alpine:3.21
 
 RUN apk add --no-cache grype bash
 

entrypoint.sh

@@ -35,7 +35,11 @@ if [ -n "$INPUT_PLATFORM" ]; then
   GRYPE_OPTIONS+=("--platform" "$INPUT_PLATFORM")
 fi
 
+if [[ "$INPUT_IMAGE_NAME" == *:* ]]; then
   GRYPE_OPTIONS+=("registry:${IMAGE_NAME}")
+else
+  GRYPE_OPTIONS+=("file:${INPUT_IMAGE_NAME}")
+fi
 
 # shellcheck disable=SC2145
 echo "Running grype container scanning with options: ${GRYPE_OPTIONS[@]} --show-suppressed"