Enforce use of datetime_with_timezone on create_table migrations

What does this MR do?

This MR enforces use of datetime_with_timezone instead of datetime or timestamp (alias of datetime) on migrations that create new tables.

There is already a cop defined (Migration/Datetime) to check for that case but it is not working properly for migrations that create new tables.

In summary:

• Update the Migration/Datetime cop to properly enforce datetime_with_timezone on migrations that create new tables.
• Disable the current database offenses caused by the Migration/Datetime cop
• Add new rspec tests for checking attributes defined as datetime_with_timezone on migrations that create new tables.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• [-] Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team

Closes #32596 (closed)