www/grafana: Update 12.3.0 => 12.3.3 (Fixes security vulnerabilities)

Changelogs:
https://github.com/grafana/grafana/releases/tag/v12.3.1
https://github.com/grafana/grafana/releases/tag/v12.3.2
https://github.com/grafana/grafana/releases/tag/v12.3.3

PR: 293245
Security: CVE-2026-21722
Security: CVE-2025-41117
MFH: 2026Q1