Defer costly parameter assignments in Seed::Build

What does this MR do and why?

Related to #385850 (closed) (main issue)

Related to #386018 (closed) (ff rollout issue)

In Skip assign tag_list and build_needs in Seed::B... (#385850 - closed), while profiling the pipeline creation and looking at Chain::Seed step, we realized that:

• Assigning tag_list to Ci::Build takes 5.4% (almost 1s) based on the profile data below.
• Assigning needs_attributes to Ci::Build takes 4.9%.
• In total we spend 2s in assigning attributes that then we persist in Bulk

In this MR we move the assignment of tag_list and needs_attributes from initial_attributes to deferred_attributes, after evaluating job rules. For example: let's supposed we have a .gitlab-ci.yml that defines 1000 jobs in total. After evaluating job rules, the pipeline contains 200 jobs.

• initial_attributes are assigned to all 1000 jobs
• deferred_attributes are assigned to the 200 jobs

There should be a performance gain by doing these heavy assignments only to jobs that are needed, given also the fact that tag_list and needs_attributes are not used for evaluating job rules.

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