Temporarily disable the mockito builder for better build perf

[sourcegraph-wk]

What/Why

This batch temporarily disables the mockito builder because it is only needed for NNBD code and the default behavior is for it to run on every .dart file and fully resolve each of those files, which is slow. Disabling this builder should improve local and CI build times.

Testing

These changes should only disable a builder that is already not generating anything for packages that have not yet migrated to null-safety. For that reason, code review of the modification to the build.yaml and passing CI should be sufficient testing.

More Info

This batch change is a part of a larger Client Platform effort to update our Dart dependencies and unblock us from upgrading to the latest Dart SDK. More info can be found here: https://wiki.atl.workiva.net/display/CP/Dependency+Upgrades

If you have any questions or comments, please comment on this PR or reach out to #support-client-plat on Slack.

_Created by Sourcegraph batch change Workiva/disable_mockito_builder._

[aviary3-wk]

Security Insights

(2) Vulnerable direct dependencies were detected

1 vulns in ansi-regex < 5.0.1 via yarn.lock

1 vulns in glob-parent < 5.1.2 via yarn.lock

Action Items

• Review dependencies for available updates
• See this Splunk dashboard for more CVE details
• Review PR for security impact; comment "security review required" if needed or unsure

• Verify aviary.yaml coverage of security relevant code

  Questions or Comments? Reach out on Slack: #support-infosec.

[robbecker-wf]

QA+1 CI Passes

[robbecker-wf]

@Workiva/release-management-p