remove tag from image name

Author: duffney

.github/workflows/attest.yml

@@ -19,7 +19,7 @@ jobs:
         uses: actions/attest@v1
         id: attest
         with:
-          subject-name: ghcr.io/yoshuawuyts/rust-wasi-hello:0.1.0
+          subject-name: ghcr.io/yoshuawuyts/rust-wasi-hello
           # subject-digest: ${{ steps.push.outputs.digest }}
           subject-digest: sha256:67940472ac167f1c79224ee645ba59ca54483d95c633f9e67a4d16719d1fa356
           predicate-type: "https://in-toto.io/attestation/release/v0.1"