revert requests from 2.32.0 to 2.31.0 (sonic-net#3154)

What I did
Use requests 2.31.0 instead of latest 2.32.0
Why I did it
requests 2.32.0 breaks Test stage.

.azure-pipelines/test-docker-sonic-vs-template.yml

@@ -83,15 +83,15 @@ jobs:
       sudo .azure-pipelines/build_and_install_module.sh
 
       sudo apt-get install -y libhiredis0.14 libyang0.16
-      sudo dpkg -i $(Build.ArtifactStagingDirectory)/download/libprotobuf*_amd64.deb $(Build.ArtifactStagingDirectory)/download/libprotobuf-lite*_amd64.deb $(Build.ArtifactStagingDirectory)/download/python3-protobuf*_amd64.deb 
+      sudo dpkg -i $(Build.ArtifactStagingDirectory)/download/libprotobuf*_amd64.deb $(Build.ArtifactStagingDirectory)/download/libprotobuf-lite*_amd64.deb $(Build.ArtifactStagingDirectory)/download/python3-protobuf*_amd64.deb
       sudo dpkg -i $(Build.ArtifactStagingDirectory)/download/libdashapi*.deb
       sudo dpkg -i --force-confask,confnew $(Build.ArtifactStagingDirectory)/download/libswsscommon_1.0.0_amd64.deb || apt-get install -f
       sudo dpkg -i $(Build.ArtifactStagingDirectory)/download/python3-swsscommon_1.0.0_amd64.deb
 
       # install packages for vs test
       sudo apt-get install -y net-tools bridge-utils vlan
       sudo apt-get install -y python3-pip
-      sudo pip3 install pytest==4.6.2 attrs==19.1.0 exabgp==4.0.10 distro==1.5.0 docker>=4.4.1 redis==3.3.4 flaky==3.7.0
+      sudo pip3 install pytest==4.6.2 attrs==19.1.0 exabgp==4.0.10 distro==1.5.0 docker>=4.4.1 redis==3.3.4 flaky==3.7.0 requests==2.31.0
     displayName: "Install dependencies"
 
   - script: |