www/grafana9: security update to 9.4.7

https://grafana.com/blog/2023/03/22/grafana-security-release-new-versions-with-security-fixes-for-cve-2023-1410/

PR: 270562
Approved by: Boris Korzun (maintainer)
MFH: 2023Q2
Security: 955eb3cc-ce0b-11ed-825f-6c3be5272acd

(cherry picked from commit 3a01bbfd5a833521c665aca61d388137b74c5237)