[VEG-638] Bump zendesk_apps_support to latest

[token-cjg]

:v:

/cc @zendesk/vegemite

Description

Let's bump zendesk_apps_support to 4.29.9, so that we have access to the latest validations.

Compare diff: https://github.com/zendesk/zendesk_apps_support/compare/v4.29.5...v4.29.9

Changes:

• https://github.com/zendesk/zendesk_apps_support/pull/306, version bump, no risk
• https://github.com/zendesk/zendesk_apps_support/pull/304, Add warning for sensitive data in hidden fields, low risk: validations might break.
• https://github.com/zendesk/zendesk_apps_support/pull/303, Add strings for new warning validation, no risk: translations only
• https://github.com/zendesk/zendesk_apps_support/pull/305, Replace mime_type gem with marcel, low risk: drop in gem replacement
• https://github.com/zendesk/zendesk_apps_support/pull/301, version bump, no risk.
• https://github.com/zendesk/zendesk_apps_support/pull/300, version bump, no risk
• https://github.com/zendesk/zendesk_apps_support/pull/297, loofah gem bump to placate snyk, low risk
• https://github.com/zendesk/zendesk_apps_support/pull/291, alter bundler versions, no risk
• https://github.com/zendesk/zendesk_apps_support/pull/289, bump saasc, medium risk
• https://github.com/zendesk/zendesk_apps_support/pull/288, version bump, no risk
• https://github.com/zendesk/zendesk_apps_support/pull/309, github action, no risk
• https://github.com/zendesk/zendesk_apps_support/pull/308, flexible: true validation change, low risk
• https://github.com/zendesk/zendesk_apps_support/pull/310, gem bump + bundler bump, no risk

4 low risks, 1 medium risk. Overall risk: medium.

Tasks

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

References

• JIRA: https://zendesk.atlassian.net/browse/VEG-638

Risks

Medium. A large number of changes for ZAS being brought in. A bit unavoidable, unless we cherrypick the flexible: true change to a separate tag. These risks are:

• https://github.com/zendesk/zendesk_apps_support/pull/289, bump saasc, medium risk
• https://github.com/zendesk/zendesk_apps_support/pull/304, Add warning for sensitive data in hidden fields, low risk: validations might break.
• https://github.com/zendesk/zendesk_apps_support/pull/305, Replace mime_type gem with marcel, low risk: drop in gem replacement
• https://github.com/zendesk/zendesk_apps_support/pull/297, loofah gem bump to placate snyk, low risk
• https://github.com/zendesk/zendesk_apps_support/pull/308, flexible: true validation change, low risk

Given the level of risk, the following things should be checked before merging this PR:

• zat server with an app should still work.
• zat validate should work for happy and for failure mode paths
• zat package should still work, as should zat new
• zat create and zat update should still work.