Update list-template.md | fix metadata to conform to new guidelines (#8368)

* Update list-template.md | fix metadata to conform to new guidelines

According to the allowed values for `ms.topic` as now showing in the Contributor's Guide (https://review.learn.microsoft.com/en-us/help/platform/metadata-taxonomies/mstopic?branch=main), the ms.topic for autogenerated reference content should be `language-reference`. By making this update, the available extensions report will also be removed from management's broken link report. We'll still be able to monitor broken links from the azure-docs-cli repo's daily build report.

* Update ms.topic to generated-reference

Author: dbradish-microsoft

scripts/ci/avail-ext-doc/list-template.md

@@ -5,12 +5,9 @@ author: haroldrandom
 ms.author: jianzen
 manager: yonzhan,yungezz
 ms.date: {{ date }}
-ms.topic: article
+ms.topic: generated-reference
 ms.service: azure-cli
-ms.devlang: azure-cli
-ms.tool: azure-cli
 ms.custom: devx-track-azurecli
-keywords: az extension, azure cli extensions, azure extensions
 ---
 
 # Available Azure CLI extensions