chore(cosign): upgrade cosign to latest version 1.9.0

Signed-off-by: Batuhan Apaydın <batuhan.apaydin@trendyol.com>

example/spiffe-vault-cosign/Dockerfile

@@ -1,9 +1,9 @@
-FROM gcr.io/projectsigstore/cosign:v1.2.1 as cosign-bin
+FROM gcr.io/projectsigstore/cosign:v1.9.1 as cosign-bin
 
 FROM docker:20.10.8 as docker-bin
 
 FROM philipssoftware/spiffe-vault:v0.2.0
 LABEL maintainer="marco.franssen@philips.com"
 ENV DOCKER_CERT_PATH=/certs/client
 COPY --from=docker-bin /usr/local/bin/docker /usr/local/bin/docker
-COPY --from=cosign-bin /bin/cosign /usr/local/bin/cosign
+COPY --from=cosign-bin /ko-app/cosign /usr/local/bin/cosign