build(deps): bump actions/attest-build-provenance from 3 to 4 (#14)

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/build.yml

@@ -69,7 +69,7 @@ jobs:
           overwrite: true
 
       - name: Attest Artifact
-        uses: actions/attest-build-provenance@v3
+        uses: actions/attest-build-provenance@v4
         with:
           subject-name: mpv-macos-26-arm64.zip
           subject-digest: sha256:${{ steps.upload.outputs.artifact-digest }}