chore: Update permissions in CreateOmikuji.yml workflow

Author: terasakisatoshi

.github/workflows/CreateOmikuji.yml

@@ -16,6 +16,8 @@ jobs:
       GKS_ENCODING: utf8
       GKSwstype: nul
     name: Julia ${{ matrix.version }} - ${{ matrix.os }} - ${{ matrix.arch }} - ${{ github.event_name }}
+    permissions:
+      contents: write
     runs-on: ${{ matrix.os }}
     timeout-minutes: 60
     permissions: # needed to allow julia-actions/cache to proactively delete old caches that it has created