Bump to 3.8.11

[token-cjg]

:v:

/cc @zendesk/vegemite

Description

Bump ZAT to 3.8.11.

Tasks

• [ ] Include comments/inline docs where appropriate
• [ ] Write tests
• [ ] Update changelog here

References

• https://github.com/zendesk/zendesk_apps_tools/pull/385

Risks

Medium. Dependabot change might break zat server or zat theme preview.

[token-cjg]

Already done, closing.