Temporary hack to correctly tag the security docker image…

.github/workflows/build-security.yml

@@ -14,7 +14,7 @@ jobs:
         env:
           TZ: Etc/UTC
         run: |
-          echo mastodon_version_prerelease=nightly.$(date --date='next day' +'%Y-%m-%d')-security>> $GITHUB_OUTPUT
+          echo mastodon_version_prerelease=nightly.2024-02-02-security>> $GITHUB_OUTPUT
     outputs:
       prerelease: ${{ steps.version_vars.outputs.mastodon_version_prerelease }}