Revert "customize docker image tag for alpine images" (microsoft#26)

This reverts commit bb4ddf6.

Author: joaomoreno

azure-pipelines.yml

@@ -31,7 +31,6 @@ jobs:
   - template: build.yml
     parameters:
       arch: alpine-x64
-      tag: alpine-311-x64
 
 - job: alpine_arm64
   pool:
@@ -41,7 +40,6 @@ jobs:
     parameters:
       qemu: 'true'
       arch: alpine-arm64
-      tag: alpine-311-arm64
 
 - job: buster_arm64
   pool:

build.yml

@@ -16,6 +16,6 @@ steps:
   inputs:
     containerRegistry: VSCodeHub
     repository: 'vscode-linux-build-agent'
-    tags: ${{ coalesce(parameters.tag, parameters.arch) }}
+    tags: ${{ parameters.arch }}
     command: push
   condition: and(succeeded(), eq(variables['Build.SourceBranch'], 'refs/heads/main'))