fix: Secure Files API secure_file_id should be required param

What does this MR do and why?

fix: Secure Files API secure_file_id should be required param

Previously, require referenced ambiguous route param :id which references the project ID instead. The validation around requires :id would fail when a string-path was provided, leading to :id is invalid

References

• No issue, noticed while reviewing cli!2069 (comment 2475873383)

How to set up and validate locally

See patch for testing previous failure, demo:

Before

❯ curl -H 'PRIVATE-TOKEN: $GL_TOKEN' http://gdk.test:3000/api/v4/projects/flipflop%2Fverify-520569/secure_files/1
{"error":"id is invalid"}%

After

❯ curl -H 'PRIVATE-TOKEN: $GL_TOKEN' http://gdk.test:3000/api/v4/projects/flipflop%2Fverify-520569/secure_files/1
{"id":1,"name":"old_query.sql","checksum":"eadccb26759413b0839d5280cba1f9bf97aa1bfebe3870dcb79581488262ec70","checksum_algorithm":"sha256","created_at":"2025-04-29T21:38:34.472Z","expires_at":null,"metadata":null,"file_extension":"sql"}%

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