Dashboard: replacement of __inputs incorrect at import for file-based provisioning

### What happened? When exporting a Dashboard as JSON and selecting the "Export the dashboard to use in another instance" option, the variables declared within the `__inputs` block are not properly replaced by Grafana at import-time, when importing that file via the (non-interactive) **file-based provisioning** approach. ### What did you expect to happen? The replacement should happen with the same level of correctness as when importing a dashboard JSON _manually_ via the Grafana UI. ### Did this work before? No idea, i have no recollection. ### How do we reproduce it? First, create an **empty dashboard.** No panels. Go to the Dashboard settings. In the **Variables** tab, create a new variable of type _Constant_. Keep its name at "query0" and give it some value (e.g. `.*`). Next, save the dashboard, then export the dashboard as JSON, checking the "Export the dashboard to use in another instance" box. You will get the following JSON: ```json { "__inputs": [ { "name": "VAR_QUERY0", "type": "constant", "label": "query0", "value": ".*", "description": "" } ], "__elements": {}, "__requires": [ { "type": "grafana", "id": "grafana", "name": "Grafana", "version": "12.1.1" } ], "annotations": { "list": [ { "builtIn": 1, "datasource": { "type": "grafana", "uid": "-- Grafana --" }, "enable": true, "hide": true, "iconColor": "rgba(0, 211, 255, 1)", "name": "Annotations & Alerts", "type": "dashboard" } ] }, "editable": true, "fiscalYearStartMonth": 0, "graphTooltip": 0, "id": null, "links": [], "panels": [], "schemaVersion": 41, "tags": [], "templating": { "list": [ { "hide": 2, "name": "query0", "query": "${VAR_QUERY0}", "skipUrlSync": true, "type": "constant", "current": { "value": "${VAR_QUERY0}", …