devel/electron26: update to 26.6.8

Changelog: https://github.com/electron/electron/releases/tag/v26.6.8

Reported by: GitHub (watch releases)
MFH: 2024Q1
Security: 13a8c4bf-cb2b-48ec-b49c-a3875c72b3e8

(cherry picked from commit 329e3223c2e8fb46134ed055de381e9f6df0ebc7)