fix: update MSSQL Server linux image's Docker registry (#26440) (#26486)

Author: mergify[bot]

x-pack/metricbeat/module/mssql/_meta/Dockerfile

@@ -1,5 +1,5 @@
 ARG MSSQL_VERSION
-FROM microsoft/mssql-server-linux:${MSSQL_VERSION}
+FROM mcr.microsoft.com/mssql/server:${MSSQL_VERSION}
 
 ENV ACCEPT_EULA='Y'
 ENV SA_PASSWORD='1234_asdf'

x-pack/metricbeat/module/mssql/_meta/supported-versions.yml

@@ -0,0 +1,2 @@
+variants:
+  - MSSQL_VERSION: 2017-GA-ubuntu

x-pack/metricbeat/module/mssql/docker-compose.yml

@@ -2,10 +2,10 @@ version: '2.3'
 
 services:
   mssql:
-    image: docker.elastic.co/integrations-ci/beats-mssql:${MSSQL_VERSION:-2017-GA}-1
+    image: docker.elastic.co/integrations-ci/beats-mssql:${MSSQL_VERSION:-2017-GA-ubuntu}-1
     build:
       context: ./_meta
       args:
-        MSSQL_VERSION: ${MSSQL_VERSION:-2017-GA}
+        MSSQL_VERSION: ${MSSQL_VERSION:-2017-GA-ubuntu}
     ports:
       - 1433