ref(repositories): Drop old project/repository columns

[wedamija]

Summary

Phase 2 of SafeRemoveField: drop the project_id and repository_id columns from sentry_repositoryprojectpathconfig and seer_projectrepository.

Phase 1 (MOVE_TO_PENDING) was deployed in #115663.

Test plan

• Migrations apply cleanly
• No code references these columns — all reads and writes were removed in prior PRs

[github-actions]

This PR has a migration; here is the generated SQL for src/sentry/migrations/1099_drop_old_fk_columns.py src/sentry/seer/migrations/0017_drop_old_fk_columns.py

for 1099_drop_old_fk_columns in sentry

--
-- Remove field project from repositoryprojectpathconfig
--
ALTER TABLE "sentry_repositoryprojectpathconfig" DROP COLUMN "project_id" CASCADE;
--
-- Remove field repository from repositoryprojectpathconfig
--
ALTER TABLE "sentry_repositoryprojectpathconfig" DROP COLUMN "repository_id" CASCADE;

for 0017_drop_old_fk_columns in seer

--
-- Remove field project from seerprojectrepository
--
ALTER TABLE "seer_projectrepository" DROP COLUMN "project_id" CASCADE;
--
-- Remove field repository from seerprojectrepository
--
ALTER TABLE "seer_projectrepository" DROP COLUMN "repository_id" CASCADE;