DevOps Pipelines: PipelineId ending up as null

Sentry Issue: [FLOWFUSE-BACKEND-1X](https://flowfuse.sentry.io/issues/4677061131/?referrer=github_integration)

```
SequelizeDatabaseError: null value in column "PipelineId" of relation "PipelineStages" violates not-null constraint
File "/usr/src/forge/app/node_modules/sequelize/lib/dialects/postgres/query.js", line 50, in Query.run
const errForStack = new Error();
File "/usr/src/forge/app/node_modules/sequelize/lib/sequelize.js", line 315, in
return await query.run(sql, bindParameters);
File "node:internal/process/task_queues", line 95, in process.processTicksAndRejections
File "/usr/src/forge/app/node_modules/sequelize/lib/dialects/abstract/query-interface.js", line 393, in PostgresQueryInterface.delete
return await this.sequelize.query(sql, options);
File "/usr/src/forge/app/node_modules/sequelize/lib/model.js", line 2627, in model.destroy
result = await this.constructor.queryInterface.delete(this, this.constructor.getTableName(options), where, __spreadValues({ type: Quer {snip}
...
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```