fix(ci): drop secret-context if:, let script own the missing-token error

The previous workflow used ``if: ${{ secrets.WIKI_SYNC_TOKEN == '' }}``
to fail fast before running the sync script. GitHub rejected the
workflow at YAML-validation time (0 jobs executed, the run went
straight to ``failure`` before any step scheduled), likely because
secret-context references inside ``if:`` can trip startup validation
when the referenced secret isn't configured.

Simpler: just let sync-wiki.sh detect the empty env var and exit 1
with its own "No token in env" message. Same UX, one fewer
YAML construct to fight.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: dotradepro

.github/workflows/sync-wiki.yml

@@ -48,13 +48,9 @@ jobs:
       - name: Checkout repo (with docs/)
         uses: actions/checkout@v4
 
-      - name: Fail fast if WIKI_SYNC_TOKEN is missing
-        if: ${{ secrets.WIKI_SYNC_TOKEN == '' }}
-        run: |
-          echo "::error::WIKI_SYNC_TOKEN secret is not set — see .github/workflows/sync-wiki.yml comment for provisioning steps." >&2
-          exit 1
-
       - name: Run sync
         env:
+          # WIKI_SYNC_TOKEN is a repo secret the maintainer sets once.
+          # sync-wiki.sh exits 1 with a clear error if it's empty.
           WIKI_SYNC_TOKEN: ${{ secrets.WIKI_SYNC_TOKEN }}
         run: bash scripts/sync-wiki.sh