Bump CS_MAJOR_VERSION from 1 to 2

What does this MR do?

The new version of the Container Scanning tool implemented by gitlab-org/security-products/analyzers/klar!11 (merged) will change the format of the report from clair-scanner to the GitLab Analyzers Common Library Format.

In order to allow Container Scanning to use this new format, we need to update the CS_MAJOR_VERSION in the Container Scanning Template which is what this MR does.

The Rails parser has already been updated to handle the new Container Scanning format in !19123 (merged)

Documentation for the new report format has been added by !20198 (merged)

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

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