ci: add minimum GitHub token permissions for workflows

Signed-off-by: Ashish Kurmi <akurmi@stepsecurity.io>

.github/workflows/buf-lint.yml

@@ -4,6 +4,9 @@ on:
     paths:
       - ".github/workflows/buf-lint.yml"
       - "**.proto"
+permissions:
+  contents: read
+
 jobs:
   buf:
     name: lint

.github/workflows/buf.yml

@@ -3,6 +3,9 @@ on:
   push:
     branches:
       - main
+permissions:
+  contents: read
+
 jobs:
   buf:
     name: lint and publish

.github/workflows/codeql-analysis.yml

@@ -6,6 +6,9 @@ on:
   schedule:
     - cron: "26 14 * * 1"
 
+permissions:
+  contents: read
+
 jobs:
   analyze:
     name: Analyze

.github/workflows/funcbench.yml

@@ -2,6 +2,9 @@ on:
   repository_dispatch:
     types: [funcbench_start]
 name: Funcbench Workflow
+permissions:
+  contents: read
+
 jobs:
   run_funcbench:
     name: Running funcbench

.github/workflows/fuzzing.yml

@@ -1,6 +1,9 @@
 name: CIFuzz
 on:
   workflow_call:
+permissions:
+  contents: read
+
 jobs:
   Fuzzing:
     runs-on: ubuntu-latest

.github/workflows/repo_sync.yml

@@ -2,6 +2,9 @@
 on:
   schedule:
     - cron: '44 17 * * *'
+permissions:
+  contents: read
+
 jobs:
   repo_sync:
     runs-on: ubuntu-latest