[build] Update Azure pipeline to use Ubuntu 24.04 image (#3916)

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#### What I did
Updated the Azure DevOps pipeline configuration to use `ubuntu-24.04` as the virtual machine image instead of `ubuntu-20.04`.

#### How I did it

#### How to verify it

#### Previous command output (if the output of a command-line utility has changed)

#### New command output (if the output of a command-line utility has changed)

Author: mssonicbld

azure-pipelines.yml

@@ -40,7 +40,7 @@ stages:
       DIFF_COVER_CHECK_THRESHOLD: 80
       DIFF_COVER_ENABLE: 'true'
     pool:
-      vmImage: ubuntu-20.04
+      vmImage: ubuntu-24.04
 
     container:
       image: sonicdev-microsoft.azurecr.io:443/sonic-slave-bookworm:$(BUILD_BRANCH)