Dashboards: Nondeterministic folder structure

### What happened? When creating folders from file structure, Grafana creates non-deterministic folder structure for the following file tree: ``` dashboards/scylladb ├── scylladb-2025.3 │   ├── alternator.2025.3.json │   ├── scylla-advanced.2025.3.json │   ├── scylla-cql.2025.3.json │   ├── scylla-detailed.2025.3.json │   ├── scylla-ks.2025.3.json │   ├── scylla-os.2025.3.json │   └── scylla-overview.2025.3.json └── scylladb-2025.3.0 ├── alternator.2025.3.0.json ├── scylla-advanced.2025.3.0.json ├── scylla-cql.2025.3.0.json ├── scylla-detailed.2025.3.0.json ├── scylla-ks.2025.3.0.json ├── scylla-os.2025.3.0.json └── scylla-overview.2025.3.0.json 3 directories, 14 files ``` It usually, as expected, creates two folders `scylladb-2025.3` and `scylladb-2025.3.0`: <img width="542" height="760" alt="Image" src="https://github.com/user-attachments/assets/a9d696c4-1ff7-40a6-ba31-bfa371749489" /> But sometimes it creates only one with both sets of dashboards. <img width="541" height="726" alt="Image" src="https://github.com/user-attachments/assets/23becc3e-53ed-4c27-9af5-2cf3d4be7b48" /> I've only ever observed this with these particular folder names. ### What did you expect to happen? Both folders should be created at all times, with their respective dashboards structured correctly. ### Did this work before? Unknown. ### How do we reproduce it? Execute the script from this archive, it will run until the returned dashboards don't match the expected list. [reproducer.tar.gz](https://github.com/user-attachments/files/21616209/reproducer.tar.gz) ### Is the bug inside a dashboard panel? No ### Environment (with versions)? Grafana: 12.0.2+security-01 (commit: 76ea754dbb0bfb3e157981ec73ba4ef1efae4207, branch: HEAD) (docker.io/grafana/grafana:12.0.2-security-01@sha256:9047b1d7ec7bfad6a7e6542e7f1782b2337e18af8ebf4f21cf5327e903dac830) OS: n/a Browser: Chromium ### Grafana platform? Kubernetes ### Datasource(s)? _No response_