Fix workflow:rules not accessing passed-upstream and trigger variables

What does this MR do?

Related to #206929 (closed)

Example CI config:

workflow:
  rules:
    - if: $SOME_VARIABLE

test:
  script: echo test

Normally, we should run this pipeline with passing SOME_VARIABLE in it. However, when running this pipeline with trigger keyword or trigger API, workflow::rules can not read the passed variable.

In Ci::CreatePipelineService, we run https://gitlab.com/gitlab-org/gitlab/-/blob/5aae54af261e21b5a17c04967d8d8f0d84730c60/lib/gitlab/ci/pipeline/chain/seed.rb#L25 in Gitlab::Ci::Pipeline::Chain::Seed section. seeds_block is passed through Ci::CreatePipelineService in the places where some attributes are passed to the to-be-created pipeline. For example; in Ci::PipelineTriggerService and Ci::CreateDownstreamPipelineService, we are using it to pass variables.

The problem is, Gitlab::Ci::Pipeline::Chain::EvaluateWorkflowRules is run before Gitlab::Ci::Pipeline::Chain::Seed, so the workflow:rules can't read the variables.

This MR fixes this.

Technical proposal origin: #206929 (comment 399503264)

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