Designate scheduled action to execute once per year

- Schedule action runner to run once per year at midnight on
  the first day of January
- Use `sha256sum` instead of `git` commit hashes for revision hash
- Set modification time of `website.tar.zst` to UNIX epoch
- Use GNU tar instead of busybox tar

.forgejo/workflows/generate.yml

@@ -2,6 +2,8 @@ name: Generate Website
 
 on:
   workflow_dispatch:
+  schedule:
+    - cron: '0 0 1 1 *'
   push:
     branches:
       - master
@@ -11,18 +13,14 @@ env:
   USER_NAME: ${{ vars.USER }}
 
 jobs:
-  build:
+  generate:
     name: Generate Website
     runs-on: docker
     container:
       image: alpine
-    strategy:
-      matrix:
-        toolchain:
-          - stable
     steps:
       - name: Install packages
-        run: apk add --no-cache nodejs git git-lfs bash curl zstd
+        run: apk add --no-cache nodejs git git-lfs bash curl tar zstd
       - name: Checkout repository
         uses: actions/checkout@v4
         with:
@@ -67,8 +65,8 @@ jobs:
         run: |
           echo "::group:: Packaging website"
           cd output
-          tar acvf website.tar.zst *
+          tar --mtime=1970-01-01 -acvf website.tar.zst *
-          echo "$(git rev-parse --short HEAD)$(git -C ../suo rev-parse --short HEAD)" > website.ver
+          SUM=$(sha256sum website.tar.zst); echo "${SUM% *}" > website.ver
           echo "::endgroup::"
       - name: Upload package 
         shell: bash