ci: remove dead BASE_TAGS reference in release bake step

steps.determine-version doesn't exist in docker-build; the expression
  resolves to empty string. The HCL default (testing) would have
  applied, but it's moot - the bake uses push-by-digest=true so tags are
  only set in merge-manifests. Dead code.

.github/workflows/release.yml

@@ -183,7 +183,6 @@ jobs:
         id: bake_vw
         uses: docker/bake-action@82490499d2e5613fcead7e128237ef0b0ea210f7 # v7.0.0
         env:
-          BASE_TAGS: "${{ steps.determine-version.outputs.BASE_TAGS }}"
           SOURCE_COMMIT: "${{ env.SOURCE_COMMIT }}"
           SOURCE_VERSION: "${{ env.SOURCE_VERSION }}"
           SOURCE_REPOSITORY_URL: "${{ env.SOURCE_REPOSITORY_URL }}"