[ci] Add permission contents:write for build job

.github/workflows/build.yml

@@ -20,6 +20,11 @@ permissions:
 jobs:
   build:
     runs-on: ${{ matrix.os }}
+    permissions:
+      # read to fetch code (actions/checkout)
+      # write to push code to gh-pages, create releases
+      # note: forked repositories will have maximum read access
+      contents: write
     continue-on-error: false
     strategy:
       matrix: