Do not specify PR SHA explicitly as that is default

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

Author: aggarg

.github/workflows/kernel-demos.yml

@@ -18,7 +18,6 @@ jobs:
       - name: Checkout Pull Request
         uses: actions/checkout@v2
         with:
-          ref:  ${{ github.event.pull_request.head.sha }}
           path: ./FreeRTOS/Source
 
       - name: Add msbuild to PATH
@@ -48,7 +47,6 @@ jobs:
       - name: Checkout Pull Request
         uses: actions/checkout@v2
         with:
-          ref:  ${{ github.event.pull_request.head.sha }}
           path: ./FreeRTOS/Source
 
       - name: Build WIN32-MingW Demo
@@ -74,7 +72,6 @@ jobs:
       - name: Checkout Pull Request
         uses: actions/checkout@v2
         with:
-          ref:  ${{ github.event.pull_request.head.sha }}
           path: ./FreeRTOS/Source
 
       - name: Install GCC
@@ -104,7 +101,6 @@ jobs:
       - name: Checkout Pull Request
         uses: actions/checkout@v2
         with:
-          ref:  ${{ github.event.pull_request.head.sha }}
           path: ./FreeRTOS/Source
 
       - name: Install MSP430 Toolchain
@@ -134,7 +130,6 @@ jobs:
       - name: Checkout Pull Request
         uses: actions/checkout@v2
         with:
-          ref:  ${{ github.event.pull_request.head.sha }}
           path: ./FreeRTOS/Source
 
       - name: Install GNU ARM Toolchain

.github/workflows/unit-tests.yml

@@ -17,7 +17,6 @@ jobs:
     - name: Checkout Pull Request
       uses: actions/checkout@v2
       with:
-        ref:  ${{ github.event.pull_request.head.sha }}
         path: ./FreeRTOS/Source
 
     - name: Setup Python