secure the github workflow

https://app.stepsecurity.io/secureworkflow/etcd-io/etcd/tests.yaml/main?enable=pin
1. Copy the existing yaml file and paste into the textbox,
2. Click "SECURE WORKFLOW"
3. Copy the manifest from the textbox and paste into etcd repo.

Signed-off-by: Benjamin Wang <wachao@vmware.com>

.github/workflows/codeql-analysis.yml

@@ -41,11 +41,11 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v2
+      uses: actions/checkout@e2f20e631ae6d7dd3b768f56a5d2af784dd54791 # v2.5.0
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v2
+      uses: github/codeql-action/init@a669cc5936cc5e1b6a362ec1ff9e410dc570d190 # v2.1.36
       with:
         languages: ${{ matrix.language }}
         # If you wish to specify custom queries, you can do so here or in a config file.
@@ -56,7 +56,7 @@ jobs:
     # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
     # If this step fails, then you should remove it and run the build manually (see below)
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v2
+      uses: github/codeql-action/autobuild@a669cc5936cc5e1b6a362ec1ff9e410dc570d190 # v2.1.36
 
     # ℹ️ Command-line programs to run using the OS shell.
     # 📚 https://git.io/JvXDl
@@ -70,4 +70,4 @@ jobs:
     #   make release
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v2
+      uses: github/codeql-action/analyze@a669cc5936cc5e1b6a362ec1ff9e410dc570d190 # v2.1.36