Switch away from AzureLinux host docker testing temporarily (#115993)

containerd on the host has a default 1024 NOFILE limit, which is not
enough for our testing. Switch to Ubuntu host testing until the changes
that increase this limit are rolled out.

Author: jakobbotsch

eng/pipelines/coreclr/templates/helix-queues-setup.yml

@@ -77,9 +77,9 @@ jobs:
     # Linux musl x64
     - ${{ if eq(parameters.platform, 'linux_musl_x64') }}:
       - ${{ if eq(variables['System.TeamProject'], 'public') }}:
-        - (Alpine.321.Amd64.Open)AzureLinux.3.Amd64.Open@mcr.microsoft.com/dotnet-buildtools/prereqs:alpine-3.21-helix-amd64
+        - (Alpine.321.Amd64.Open)Ubuntu.2204.Amd64.Open@mcr.microsoft.com/dotnet-buildtools/prereqs:alpine-3.21-helix-amd64
       - ${{ if eq(variables['System.TeamProject'], 'internal') }}:
-        - (Alpine.321.Amd64)AzureLinux.3.Amd64@mcr.microsoft.com/dotnet-buildtools/prereqs:alpine-3.21-helix-amd64
+        - (Alpine.321.Amd64)Ubuntu.2204.Amd64@mcr.microsoft.com/dotnet-buildtools/prereqs:alpine-3.21-helix-amd64
 
     # Linux musl arm32
     - ${{ if eq(parameters.platform, 'linux_musl_arm') }}: