Grafana do not start after upgrade to 12.1

### What happened? Apparently Grafana is not able to start after upgrading to version 12.1. I'm running it on k8s via official helm chart with postgresql as DB backend. Here the latest lines of logs that I can see before it hangs: ``` t=2025-08-22T07:23:22.985718052Z level=debug msg="Successfully started backend plugin process" logger=plugins.registration t=2025-08-22T07:23:22.985725569Z level=error msg="Could not register plugin" pluginId=table error="plugin table is already registered" logger=plugins.initialization t=2025-08-22T07:23:22.98573039Z level=error msg="Could not initialize plugin" pluginId=table error="plugin table is already registered" logger=plugin.grafana-azure-monitor-datasource t=2025-08-22T07:23:22.98573974Z level=debug msg="Successfully started backend plugin process" logger=plugin.mssql t=2025-08-22T07:23:22.985743409Z level=debug msg="Successfully started backend plugin process" logger=plugin.grafana-postgresql-datasource t=2025-08-22T07:23:22.985747144Z level=debug msg="Successfully started backend plugin process" logger=plugin.loader t=2025-08-22T07:23:22.985752809Z level=debug msg=Initialized class=core duration=156.054µs logger=plugin.loader source=core t=2025-08-22T07:23:22.985765255Z level=debug msg="Plugin source loaded" plugins="alertlist, alertmanager, annolist, barchart, bargauge, candlestick, canvas, cloudwatch, dashboard, dashlist, datagrid, debug, elasticsearch, flamegraph, gauge, geomap, gettingstarted, grafana, grafana-azure-monitor-datasource, grafana-postgresql-datasource, grafana-pyroscope-datasource, grafana-testdata-datasource, graphite, heatmap, histogram, influxdb, jaeger, live, logs, logs-new, loki, mixed, mssql, mysql, news, nodeGraph, opentsdb, parca, piechart, prometheus, stackdriver, stat, state-timeline, status-history, table, tempo, text, timeseries, traces, trend, welcome, xychart, zipkin" duration=87.098956ms logger=plugin.store t=2025-08-22T07:23:22.985776672Z level=info msg="Plugins loaded" count=53 duration=87…