chore: Set permissions for GitHub actions

.github/workflows/contrib.yml

@@ -4,8 +4,13 @@ on:
     branches:
       - master
 
+permissions:
+  contents: read
+
 jobs:
   deploy:
+    permissions:
+      contents: write  # for Git to git push
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3

.github/workflows/main.yml

@@ -9,6 +9,9 @@ defaults:
   run:
     shell: bash
 
+permissions:
+  contents: read
+
 jobs:
   # Check Code style quickly by running `rustfmt` over all code
   rustfmt:
@@ -149,13 +152,17 @@ jobs:
         sh linkcheck.sh --all cargo
 
   success:
+    permissions:
+      contents: none
     name: bors build finished
     needs: [docs, rustfmt, test, resolver, build_std]
     runs-on: ubuntu-latest
     if: "success() && github.event_name == 'push' && github.ref == 'refs/heads/auto-cargo'"
     steps:
     - run: echo ok
   failure:
+    permissions:
+      contents: none
     name: bors build finished
     needs: [docs, rustfmt, test, resolver, build_std]
     runs-on: ubuntu-latest