Stop using Ubuntu 20.04 (#51317)

Author: NikolaMilosavljevic

src/SourceBuild/content/eng/pipelines/source-build-sdk-diff-tests.yml

@@ -25,7 +25,7 @@ trigger: none
 
 pool:
   name: NetCore1ESPool-Svc-Internal
-  demands: ImageOverride -equals 1es-ubuntu-2004
+  demands: ImageOverride -equals 1es-ubuntu-2204
 
 parameters:
 - name: dotnetDotnetRunId

src/SourceBuild/content/eng/pipelines/templates/jobs/sdk-diff-tests.yml

@@ -20,7 +20,7 @@ jobs:
   timeoutInMinutes: 150
   pool:
     name: NetCore1ESPool-Svc-Internal
-    demands: ImageOverride -equals 1es-ubuntu-2004
+    demands: ImageOverride -equals 1es-ubuntu-2204
   variables:
   - template: ../variables/pipelines.yml
   steps:

src/SourceBuild/content/eng/pipelines/templates/stages/vmr-scan.yml

@@ -7,7 +7,7 @@ stages:
     displayName: Tag & Scan
     pool:
       name: $(DncEngInternalBuildPool)
-      image: 1es-ubuntu-2004
+      image: 1es-ubuntu-2204
       os: linux
 
     steps: