chore: add permissions section to workflow files for clarity

Author: srajasimman

.github/workflows/time-to-review.yml

@@ -4,6 +4,10 @@ on:
   pull_request:
     types: [opened, synchronize]
 
+permissions:
+  pull-requests: read
+  issues: write
+
 jobs:
   time-to-review:
     runs-on: ubuntu-latest

.github/workflows/validate-commits.yml

@@ -4,6 +4,10 @@ on:
   pull_request:
     types: [opened, synchronize, reopened]
 
+permissions:
+  contents: read
+  pull-requests: write
+
 jobs:
   validate-commits:
     runs-on: ubuntu-latest