[MM-62409] Generate and publish code coverage for webapp (#31144)

* Generate and publish code coverage for webapp

* Upate coverage output path

* Simplify coverage patterns

* Disable coverage file search

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Co-authored-by: Mattermost Build <build@mattermost.com>

.github/workflows/webapp-ci-pr.yml

@@ -18,3 +18,4 @@ concurrency:
 jobs:
   pr-ci:
     uses: ./.github/workflows/webapp-ci-template.yml
+    secrets: inherit