just db-seed should be idempotent.

[rgreinho]

Feature request

A nice to have feature would be to be able to run db-seed several times without error.

Current Behavior

If the database was previously seeded, the seeder script fails because the data is already there:

 bna-api on  docs via 🦀 v1.88.0
╰❯ just db-seed
cargo run --example seeder
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.57s
     Running `target/debug/examples/seeder`
[examples/seeder.rs:235:5] bna_core_services.len() = 10

╭ bna-api on  docs via 🦀 v1.88.0
╰❯ just db-seed
cargo run --example seeder
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.57s
     Running `target/debug/examples/seeder`
Error: Execution Error: error returned from database: duplicate key value violates unique constraint "city_pkey"

Caused by:
   0: error returned from database: duplicate key value violates unique constraint "city_pkey"
   1: error returned from database: duplicate key value violates unique constraint "city_pkey"
   2: duplicate key value violates unique constraint "city_pkey"

Location:
    examples/seeder.rs:225:5
error: Recipe `db-seed` failed on line 77 with exit code 1

Expected Behavior

Not the end of the world, but the script should either provide a nicer error message, or better being idempotent.