Ensure checkout@v2 does not persist creds (#230)

Author: nicholasberlin

.github/workflows/build.yml

@@ -26,6 +26,8 @@ jobs:
     runs-on: ${{ inputs.runner }}
     steps:
       - uses: actions/checkout@v2
+        with:
+          persist-credentials: false
       - name: Configure System
         run: |
           sudo apt-get update -y

.github/workflows/multikernel-tester.yml

@@ -39,6 +39,8 @@ jobs:
     steps:
     - name: Checkout repository
       uses: actions/checkout@v2
+      with:
+        persist-credentials: false
     - name: Install packages needed for testing
       run: |
         sudo apt-get update