Dashboards load much more slowly for non-admin users than administrators after upgrading

### Describe the bug

After upgrading Metabase, the same dashboard displays its charts quickly when signed in as an administrator, but takes noticeably longer when signed in as a non-admin account used for viewing dashboards.

This report concerns the performance difference between the two accounts. The exact root cause and whether it is a version regression have not yet been established.

### To Reproduce

On the affected installation:

1. Sign in with an administrator account and open a dashboard.
2. Observe how quickly its charts appear.
3. Sign in with a non-admin account that has access to that dashboard.
4. Open the same dashboard, tab, and filters.
5. Observe that the non-admin account takes substantially longer to display the charts.
6. Compare the two accounts again with the same conditions.

This currently reproduces on the affected installation. A clean Sample Database reproduction is not yet available.

### Expected behavior

Both accounts should be able to view the dashboard responsively while retaining their intended permissions.

### Logs

Not included in this public report.

### Information about your Metabase installation

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Deployment and infrastructure details are omitted from this public report pending approval to disclose sanitized diagnostics.
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### Severity

The delay makes the dashboard difficult to use for the non-admin viewer. The administrator experience is considerably faster.

### Additional context

The regression was noticed after an upgrade, but the precise last-known-good version has not yet been confirmed.

This may be related in symptoms to #47276, but that historical issue is closed and we have not established that the root cause is the same.

Detailed internal diagnostics have deliberately not been attached. Please indicate which minimal, sanitized information is needed for triage.