www/grafana: Update 12.0.0 => 12.0.1 (Fixes security vulnerabilities)

Release Notes:
https://grafana.com/blog/2025/05/23/grafana-security-release-medium-and-high-severity-security-fixes-for-cve-2025-4123-and-cve-2025-3580/

Changelog:
https://github.com/grafana/grafana/releases/tag/v12.0.1

Update ONLY_FOR_ARCHS.
Remove go version after default go version was increased to 1.24.

PR: 287019
Security: CVE-2025-4123
Security: CVE-2025-3580
MFH: 2025Q2