refactor(db): drop the unused raw document provider seeder

seedDocumentProviders() had no caller left: the migration that creates the
tables and DocumentProviderSeeder both import only the DOCUMENT_PROVIDERS and
DOCUMENT_PROVIDER_FIELDS constants. Its two INSERT OR IGNORE statements were
the only SQLite-only spellings in the file and had been baselined rather than
removed. Deleting it lets the file leave the dialect baseline (13 hits down to
11) and the better-sqlite3 import allowlist in eslint.config.mjs, since nothing
in it touches the driver any more. DOCUMENT_PROVIDER_SEED_IDS goes with it, it
had no importer either.

server/scripts/dialect-baseline.json

@@ -1,7 +1,4 @@
 {
-  "src/db/document-provider-seed.ts": {
-    "insert-or": 2
-  },
   "src/db/entities/IdempotencyKeys.entity.ts": {
     "strftime": 1
   },