Add read-all default permission to remaining github workflows templates (#1145)

.github/workflows/beta.yml

@@ -1,5 +1,8 @@
 name: Beta Branch CI
 
+# Declare default permissions as read only.
+permissions: read-all
+
 on:
   push:
     branches: [beta]

.github/workflows/gh-pages.yml

@@ -1,4 +1,8 @@
 name: Deploy to GitHub Pages
+
+# Declare default permissions as read only.
+permissions: read-all
+
 on:
   push:
     branches:

.github/workflows/main.yml

@@ -1,5 +1,8 @@
 name: Master Branch CI
 
+# Declare default permissions as read only.
+permissions: read-all
+
 on:
   push:
     branches: [ master ]

.github/workflows/verify-web-demos.yml

@@ -1,4 +1,8 @@
 name: Verify web demos
+
+# Declare default permissions as read only.
+permissions: read-all
+
 on: [push, pull_request]
 jobs:
   verify-web-demos: