Fix postprovision hook to explicitly use bash for script execution on posix systems

Author: Harsh-Microsoft

azure.yaml

@@ -14,7 +14,7 @@ hooks:
   postprovision:
     posix:
       shell: sh
-      run: sed -i 's/\r$//' ./infra/scripts/post_deployment.sh; ./infra/scripts/post_deployment.sh
+      run: sed -i 's/\r$//' ./infra/scripts/post_deployment.sh; bash ./infra/scripts/post_deployment.sh
       interactive: true
     windows:
       shell: pwsh