Update conditionalAccessGapAnalyzer.workbook

[Palciny]

conditionalAccessGapAnalyzer.workbook is including "Windows SignIn" that doesn't support MFA, so it doesn't have sense to be included in the report.

There was also request for this change:

https://github.com/microsoft/Application-Insights-Workbooks/issues/1824

PR Checklist

• [x] Explain your changes, so people looking at the PR know what and why, the code changes are the how.
• [x] Validate your changes using one or more of the testing methods.

If adding or updating templates:

• [ ] post a screenshot of templates and/or gallery changes
• [ ] ensure your template has a corresponding gallery entry in the gallery folder
• [ ] If you are adding a new template, add your team and template/gallery file(s) to the CODEOWNERS file. CODEOWNERS entries should be teams, not individuals
• [ ] ensure all steps have meaningful names
• [ ] ensure all parameters and grid columns have display names set so they can be localized
• [ ] ensure that parameters id values are unique or they will fail PR validation (parameter ids are used for localization)
• [ ] ensure that steps names are unique or they will fail PR validation (step names are used for localization)
• [ ] grep /subscription/ and ensure that your parameters don't have any hardcoded resourceIds or they will fail PR validation
• [ ] remove fallbackResourceIds and fromTemplateId fields from your template workbook or they will fail PR validation