Remove direct dependency on Azure/go-autorest/autorest/adal

[chrisberkhout]

Proposed commit message

Remove direct dependency on Azure/go-autorest/autorest/adal

Remove direct use of the deprecated autorest/adal, replacing it with
azidentity, as described in the migration guide[1].

Indirect dependencies remain:

- github.com/elastic/beats/v7/x-pack/filebeat/input/o365audit
  - github.com/Azure/go-autorest/autorest
    - github.com/Azure/go-autorest/autorest/adal

- github.com/elastic/beats/v7/x-pack/filebeat/input/azureeventhub
  - github.com/Azure/azure-event-hubs-go/v3/storage
    - github.com/Azure/go-autorest/autorest/adal

- github.com/elastic/beats/v7/x-pack/metricbeat/module/azure/app_insights
  - github.com/Azure/go-autorest/autorest
    - github.com/Azure/go-autorest/autorest/adal

[1]: https://github.com/Azure/azure-sdk-for-go/blob/main/sdk/azidentity/MIGRATION.md

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

Related issues

• Relates Remove deprecated package autorest/adal from beats #41463

[mergify]

This pull request does not have a backport label.
If this is a bug or security fix, could you label this PR @chrisberkhout? 🙏.
For such, you'll need to label your PR with:

• The upcoming major version of the Elastic Stack
• The upcoming minor version of the Elastic Stack (if you're not pushing a breaking change)

To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-8./d is the label to automatically backport to the 8./d branch. /d is the digit
• backport-active-all is the label that automatically backports to all active branches.
• backport-active-8 is the label that automatically backports to all active minor branches for the 8 major.
• backport-active-9 is the label that automatically backports to all active minor branches for the 9 major.

[elasticmachine]

Pinging @elastic/security-service-integrations (Team:Security-Service Integrations)