fix: goreleaser cosign step (#2568)

Signed-off-by: Charles-Edouard Brétéché <[email protected]>

Author: eddycharly

.goreleaser.yaml

@@ -61,7 +61,6 @@ kos:
 
 signs:
   - cmd: cosign
-    certificate: '${artifact}.pem'
     signature: "${artifact}.sigstore.json"
     args:
       - sign-blob