Use prebuilt docker images instead of installing dependencies on every run (#9671)

Author: dibarbet

azure-pipelines.yml

@@ -86,11 +86,10 @@ stages:
       # Prefer the dotnet from the container.
       installDotNet: false
       testVSCodeVersion: $(testVSCodeVersion)
-      installAdditionalLinuxDependencies: true
       pool:
         name: NetCore-Public
         demands: ImageOverride -equals build.ubuntu.2204.amd64.open
-      containerName: mcr.microsoft.com/dotnet/sdk:8.0-noble
+      containerName: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-24.04-net8.0-vscode-csharp-amd64
 
 - stage:
   displayName: Test Linux (.NET 9)
@@ -104,11 +103,10 @@ stages:
       # Prefer the dotnet from the container.
       installDotNet: false
       testVSCodeVersion: $(testVSCodeVersion)
-      installAdditionalLinuxDependencies: true
       pool:
         name: NetCore-Public
         demands: ImageOverride -equals build.ubuntu.2204.amd64.open
-      containerName: mcr.microsoft.com/dotnet/sdk:9.0-noble
+      containerName: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-24.04-net9.0-vscode-csharp-amd64
 
 - stage:
   displayName: Test Linux (.NET 10)
@@ -120,11 +118,10 @@ stages:
       # Prefer the dotnet from the container.
       installDotNet: false
       testVSCodeVersion: $(testVSCodeVersion)
-      installAdditionalLinuxDependencies: true
       pool:
         name: NetCore-Public
         demands: ImageOverride -equals build.ubuntu.2204.amd64.open
-      containerName: mcr.microsoft.com/dotnet/sdk:10.0-noble
+      containerName: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-24.04-net10.0-vscode-csharp-amd64
 
 - stage:
   displayName: Test Linux (.NET 11)
@@ -136,11 +133,10 @@ stages:
       # Prefer the dotnet from the container.
       installDotNet: false
       testVSCodeVersion: $(testVSCodeVersion)
-      installAdditionalLinuxDependencies: true
       pool:
         name: NetCore-Public
         demands: ImageOverride -equals build.ubuntu.2204.amd64.open
-      containerName: mcr.microsoft.com/dotnet/sdk:11.0-preview
+      containerName: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-26.04-net11.0-vscode-csharp-amd64
 
 - stage: Test_Windows_Stage
   displayName: Test Windows

azure-pipelines/test-linux-docker-prereqs.yml

@@ -8,9 +8,6 @@ parameters:
     default: ''
   - name: installDotNet
     type: boolean
-  - name: installAdditionalLinuxDependencies
-    type: boolean
-    default: false
   - name: testVSCodeVersion
     type: string
 
@@ -40,7 +37,6 @@ jobs:
   - template: /azure-pipelines/test.yml@self
     parameters:
       installDotNet: ${{ parameters.installDotNet }}
-      installAdditionalLinuxDependencies: ${{ parameters.installAdditionalLinuxDependencies }}
       npmCommand: $(npmCommand)
       testVSCodeVersion: ${{ parameters.testVSCodeVersion }}
       isIntegration: $(isIntegration)

azure-pipelines/test-matrix.yml

@@ -1,9 +1,6 @@
 parameters:
   - name: installDotNet
     type: boolean
-  - name: installAdditionalLinuxDependencies
-    type: boolean
-    default: false
   - name: npmCommand
     type: string
   - name: testVSCodeVersion
@@ -22,12 +19,7 @@ steps:
   parameters:
     installDotNet: ${{ parameters.installDotNet }}
 
-- ${{ if eq(parameters.installAdditionalLinuxDependencies, true) }}:
-  - template: test-linux-docker-prereqs.yml
-
 - template: test-prereqs.yml
-  parameters:
-    installAdditionalLinuxDependencies: ${{ parameters.installAdditionalLinuxDependencies }}
 
 - script: npm run ${{ parameters.npmCommand }}
   displayName: 🧪 Run $(Agent.JobName)