Add permissions that were missed on the first pass

Author: otelbot[bot]

.github/workflows/backport.yml

@@ -9,6 +9,8 @@ on:
 jobs:
   backport:
     runs-on: ubuntu-latest
+    permissions:
+      contents: write  # required for pushing changes
     steps:
       - run: |
           if [[ ! $GITHUB_REF_NAME =~ ^release/v[0-9]+\.[0-9]+\.x-0\.[0-9]+bx$ ]]; then

.github/workflows/prepare-patch-release.yml

@@ -5,6 +5,8 @@ on:
 jobs:
   prepare-patch-release:
     runs-on: ubuntu-latest
+    permissions:
+      contents: write  # required for pushing changes
     steps:
       - uses: actions/checkout@v4
 

.github/workflows/prepare-release-branch.yml

@@ -41,6 +41,8 @@ jobs:
   create-pull-request-against-release-branch:
     runs-on: ubuntu-latest
     needs: prereqs
+    permissions:
+      contents: write  # required for pushing changes
     steps:
       - uses: actions/checkout@v4
 
@@ -117,6 +119,8 @@ jobs:
   create-pull-request-against-main:
     runs-on: ubuntu-latest
     needs: prereqs
+    permissions:
+      contents: write  # required for pushing changes
     steps:
       - uses: actions/checkout@v4