Philimon/add fail safe for beta split reporting

[philimon-reset]

Relevant Links

Description of Code / Doc Changes

• add failsafe for beta split reporting.
• if a site/region mappings has all the tests skipped, then it won't be added to the beta split mapping list.

Process Changes Required

Mark the relevant boxes:

• Changes CI flow
• Changes L10n harness

Screenshots or Explanations

If you need to explain your code, do it here.

Comments or Future Work

• better check in the future. currently only checks if the skip field is true, but doesn't take into account skipped field.

Workflow Checklist

• Please request reviewers
• If this is an unblocker, please post in Slack.
• If asked to address comments, please resolve conversations.
• If asked to change code, please re-request review from the person who wanted changes.

Thank you!