fix: clean /tmp/silo before cloning in docs workflows

The docs runner persists state between runs, so /tmp/silo may
already exist from a previous (possibly failed) run.

.gitea/workflows/docs.yml

@@ -33,6 +33,7 @@ jobs:
 
       - name: Fetch Silo server docs
         run: |
+          rm -rf /tmp/silo
           git clone --depth 1 --filter=blob:none --sparse \
             http://gitea:3000/kindred/silo.git /tmp/silo
           cd /tmp/silo

.gitea/workflows/sync-silo-docs.yml

@@ -22,6 +22,7 @@ jobs:
 
       - name: Clone Silo server docs
         run: |
+          rm -rf /tmp/silo
           git clone --depth 1 --filter=blob:none --sparse \
             http://gitea:3000/kindred/silo.git /tmp/silo
           cd /tmp/silo