Consolidate let declarations and before blocks from unnecessarily nested contexts

What does this MR do and why?

I'm adding to this spec file, and in my read of it I've realized that there's some unnecessary nesting and division of test setup.

I removed a completely unused let(:build) and collapsed the outer contexts into one with a more readable description.

References

I found it helpful to collapse the individual endpoint contexts in my text editor. This view makes the redundancy pretty clear:

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

How to set up and validate locally

• There are no functional changes in this spec. The let block I removed was unused.
• The execution remains the same; there are no changes in test setups, assertions, or outcomes.
• For reviewers: I separated the indention changes into their own commit to make this MR easier to review. I highly recommend reading the first commit to see what's actually moving, and verify that there are no functional changes. After that the second commit can be reviewed and confirmed are purely whitespace with no syntactical changes.