fix: CVE-2025-66506 - upgrade cosign to 2.6.2

Signed-off-by: Shubham Bhardwaj <shubbhar@redhat.com>

Author: infernus01

go.mod

@@ -198,7 +198,7 @@ func cosignSigner(ctx context.Context, secretPath string, privateKey []byte) (*S
 	if err != nil {
 		return nil, errors.Wrap(err, "reading cosign.password file")
 	}
-	signer, err := cosign.LoadPrivateKey(privateKey, password)
+	signer, err := cosign.LoadPrivateKey(privateKey, password, nil)
 	if err != nil {
 		return nil, err
 	}

go.sum

@@ -236,7 +236,7 @@ func setupSecret(ctx context.Context, t *testing.T, c kubernetes.Interface, opts
 		}
 		s.StringData[p] = string(b)
 	}
-	cosignPriv, err := cosign.LoadPrivateKey([]byte(s.StringData["cosign.key"]), []byte(s.StringData["cosign.password"]))
+	cosignPriv, err := cosign.LoadPrivateKey([]byte(s.StringData["cosign.key"]), []byte(s.StringData["cosign.password"]), nil)
 	if err != nil {
 		t.Fatal(err)
 	}