ci: Double-quote variables in GitHub Actions

This is best practice for shell scripts.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>

.github/workflows/mshv-integration.yaml

@@ -38,7 +38,7 @@ jobs:
         run: |
           set -e
           echo "Connecting to the VM via SSH..."
-          ssh -i ~/.ssh/${KEY} -o StrictHostKeyChecking=no ${USERNAME}@${PRIVATE_IP} << EOF
+          ssh -i ~/.ssh/"${KEY}" -o StrictHostKeyChecking=no -- "${USERNAME}@${PRIVATE_IP}" << EOF
             set -e
             echo "Logged in successfully."
             export PATH="\$HOME/.cargo/bin:\$PATH"
@@ -87,9 +87,7 @@ jobs:
           PRIVATE_IP: ${{ needs.infra-setup.outputs.PRIVATE_IP }}
           USERNAME: ${{ secrets.MSHV_USERNAME }}
         run: |
-          ssh -i ~/.ssh/${KEY} -o StrictHostKeyChecking=no ${USERNAME}@${PRIVATE_IP} << EOF
-            sudo dmesg
-          EOF
+          ssh -i ~/.ssh/"${KEY}" -o StrictHostKeyChecking=no -- "${USERNAME}@${PRIVATE_IP}" sudo dmesg
 
       - name: Dump serial console logs
         if: always()
@@ -111,8 +109,8 @@ jobs:
         env:
           RG: MSHV-INTEGRATION-${{ github.run_id }}
         run: |
-          if az group exists --name ${RG}; then
-            az group delete --name ${RG} --yes --no-wait
+          if az group exists --name "${RG}"; then
+            az group delete --name "${RG}" --yes --no-wait
           else
             echo "Resource Group ${RG} does not exist. Skipping deletion."
           fi
@@ -122,8 +120,8 @@ jobs:
         env:
           KEY: azure_key_${{ github.run_id }}
         run: |
-          if [ -f ~/.ssh/${KEY} ]; then
-            rm -f ~/.ssh/${KEY} ~/.ssh/${KEY}.pub
+          if [ -f ~/.ssh/"${KEY}" ]; then
+            rm -f ~/.ssh/"${KEY}" ~/.ssh/"${KEY}.pub"
             echo "SSH key deleted successfully."
           else
             echo "SSH key does not exist. Skipping deletion."